- web.nioch.nsc.ruweb.nioch.nsc.ru/apes2016/files/APES 2016_book of... · Beijing, China (2012) and Nara, Japan (2014), I can confidently say that the Symposium is going from strength

N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS

International Tomography Center SB RAS A.E. Favorsky Irkutsk Institute of Chemistry SB RAS

Novosibirsk State University

APES 2016 Asia-Pacific EPR/ESR Symposium 2016

BOOK OF ABSTRACTS

28 August - 02 September 2016 Lake Baikal, Irkutsk, Russia

"Asia-Pacific EPR/ESR Symposium 2016":

Book of Abstracts

The most of abstracts are printed as presented, and all responsibilities should be addressed to authors.

Compiled by Dr. Denis A. Morozov

http://www.apes2016.org

© N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS

APES 2016 Symposium, 28 August – 02 September 2016, Lake Baikal, Irkutsk, Russia

3

Welcome to Asia-Pacific EPR/ESR Symposium 2016

On behalf of Local Organizing Committee, let us welcome all participants of the Asia-Pacific

EPR/ESR Symposium to be held by beautiful Lake Baikal, near Irkutsk, Russia, on 28 August – 2

September 2016. The Symposium will be held in Mayak Hotel,

Listvyank on the shore of Lake Baikal near Irkutsk city, Russia. Lake

Baikal is an ancient, massive lake in the mountainous Russian region of

Siberia, north of the Mongolian border and is the deepest lake in the

world and the largest freshwater lake by volume in the world.[The

village of Listvyanka, on its western shoreline, is a popular starting

point for summertime wildlife-spotting tours.

APES 2016 is the tenth symposium following the successful

APES 1997 (Hong Kong, China), APES 1999 (Hangzhou, China), APES

2001 (Kobe, Japan), APES 2004 (Bangalore, India), APES 2006

(Novosibirsk, Russia), APES 2008 (Cairns, Australia), APES 2010 (Jeju,

Korea), APES 2012 (Beijing, China) and the Joint Conference of

APES2014, APES-IES-SEST2014 (Nara, Japan). APES series is in the

second round and it is coming back to Russia again.

Asia-Pacific EPR/ESR Symposium aims at covering all subareas of

EPR/ESR. Contributions dealing with different aspects of recent

developments and applications in the theory, applications, methodology,

instrumentation and experimental techniques are invited (CW EPR/ESR, pulsed EPR, high

frequency and high field EPR, ENDOR, PEDLOR/DEER, time resolved EPR, FMR, MRI, CIDEP,

ODMR). Scientific program of the Symposium includes plenary lectures, invited and contributed

talks and poster sessions.

APES 2016 will be an excellent place for exchanging scientific ideas with strong friendship

among the participants from not only Asia-Pacific region but all over the world. We sincerely hope

that the scope of the symposium will serve the interest of the scientific community, as well as the

industry and the general public.

We are grateful for all the sponsors supporting this conference. They are listed on the following

pages.

We welcome all participants of the APES 2016 and are looking forward to exciting lectures,

poster contributions and interesting scientific discussions. Finally we would like to thank all of you

for coming.

Prof. Elena Bagryanskaya / Chairperson APES 2016

Organizing Committee

Vice President of International EPR (ESR) Society

and Asia-Pacific EPR/ESR Society

NIOCH SB RAS, Novosibirsk, Russia

Prof. Matvey Fedin / Co-chairman APES 2016

Organizing Committee

ITC SB RAS, Novosibirsk, Russia

https://en.wikipedia.org/wiki/Lake_Baikal#cite_note-cnn-4


4


The International EPR (ESR) Society (IES) would like to

congratulate Prof. Elena Bagryanskaya and Prof. Matvey Fedin for their

initiatives to organize Asia-Pacific EPR/ESR Symposium 2016 by the

beautiful Lake Baikal, near Irkutsk, Russia, on 28 August – 2 September

2016.

Following the tradition of Asia-Pacific EPR/ESR Symposium, I am

very happy to see that the program covers the wide research areas of

EPR/ESR in physics, chemistry, biology and medicine, material science,

and instrumentations. We can also see that distinguished guest speakers

from all over the world in the program. I am sure that the interactions

between these gusts and Asia-Pacific EPR/ESR Society (APES) members, especially the young

scientists, will encourage the EPR/ESR researches in Asia-Pacific area.

IES is also proud to announce that IES Poster Awards will be provided during the Asia-Pacific

EPR/ESR Symposium, which started since the previous APES-IES-SEST 2014 in Nara, Japan. IES

is putting some efforts to the activities of IES Poster Awards all over the world, and they were

already provided at the Royal Society Meeting, AWEST, the Rocky Mountain Conference in 2016.

They will be provided also at the EF-EPR Meeting in Torino, Italy this September. I hope the young

scientists will put all of their efforts during the poster sessions.

I wish all participants a stimulating symposium with exciting lectures, challenging questions,

interesting results, hot discussions during the poster sessions.

Prof. Hitoshi Ohta, President of International EPR (ESR) Society


5


Dear Colleagues and Friends,

It is with great pleasure that I welcome you all to the 10th

Asia-Pacific EPR/ESR Symposium on behalf of the Council of

the Asia-Pacific EPR/ESR Society (APES). With this, we

come to the birth – country of EPR a second time; the first time

was exactly 10 years ago when we met in Novosibirsk in 2006.

As a person who had the good fortune of participating in all the

nine previous Symposia, starting with the first one at Hong

Kong, China in 1997, followed by Hangzhou, China (1999),

Kobe, Japan (2001), Bangalore, India (2004), Novosibirsk,

Russia (2006), Cairns, Australia, (2008), Jeju, Korea (2010),

Beijing, China (2012) and Nara, Japan (2014), I can

confidently say that the Symposium is going from strength to

strength with each passing meeting. APES itself has become more broad-based with more countries

from the region, such as Philippines, Thailand and Turkey joining it in recent years.

This is only to be expected since the research in EPR, as in every other scientific field is

progressing at such a high pace that it has become difficult to keep abreast with the activity by

reading journal articles alone: there are simply too many of them. Various alternatives such as

abstracting services, content pages and citation alerts have come up to address this issue. However,

the most efficient way of coming to know of cutting- edge rese rch in one’s re is by ttending

conferences and meeting and discussing with colleagues with similar interests. This often leads to

cross-fertilization of ideas and also to fruitful collaborations. Thus participation in and organization

of scientific meetings have become very important parts of profession of science.

Having said that, we also recognize that organization of such Symposia/Conferences is not an

easy task. While the main aim of APES is to promote such Symposia on a biennial basis, it provides

only a benign umbrella under which the respective organizers have to do all the hard work. It is for

this reason that we are all grateful to Prof. Elena Bagryanskaya, the Conference Chair, Prof. Matvey

Fedin, the Conference Co-Chair and Dr. Dmitriy Polovyanenko, the Conference Secretary and

members of the Local Organizing Committee who have succeeded in chalking out an exciting

programme which covers the breadth, depth and vitality of the field of EPR/ESR and in making all

the necessary arrangements for the Symposium. Because of their efforts we can all look forward to

a fulfilling week ahead.

HAPPY RESONATING!

Prof. Subray V. Bhat, President of Asia-Pacific EPR/ESR Society


6

Organizers:

Sponsors:

The organizers gratefully acknowledge the support of sponsors

FASO Russia FEDERAL AGENCY FOR SCIENTIFIC ORGANIZATIONS


7

Organization of APES 2016

International Advisory Board

Prof. Subray Bhat (India)

Prof. Hitoshi Ohta (Japan)

Prof. Takeji Takui (Japan)

Prof. Simon Drew (Australia/New Zealand)

Prof. Yong Li (China)

Prof. K. N. Anuradha (India)

Prof. Tadaaki Ikoma (Japan)

Prof. Kev Salikhov (Russia)

Prof. Renad Sagdeev (Russia)

Prof. Hong-In Lee (Korea)

Prof. Noppawan P. Morales (Thailand)

Prof. Muhammed Acikgoz (Turkey)

Prof. Sa-Ouk Kang (Korea)

Prof. Czeslaw Rudowicz (Poland)

Local Organizing Committee (Russia)

Chairperson

Prof. Elena Bagryanskaya (1,6)

Co-chairman

Prof. Matvey Fedin (2,6)

Secretary

Dr. Dmitriy Polovyanenko (1)

Prof. Sergey Dzuba (3,6)

Prof. Andrei Ivanov (4)

Prof. Leonid Shundrin (1,6)

Prof. Vladimir Nadolinny (5)

Prof. Evgeniy Tretyakov (1,6)

Dr. Sergey Veber (2,6)

Dr. Denis Morozov (1,6)

Dr. Irina Irtegova (1)

Dr. Mariya Edeleva (1,6)

Mr. Denis Abashev (1)

Mrs. Irina Anisimova (1)

Mr. Andrei Kuzhelev (1,6)

(1) N.N. Vorozhtsov Novosibirsk institute of Organic Chemistry Siberian Branch of Russian

Academy of Sciences

(2) International Tomography Center Siberian Branch of Russian Academy of Sciences

(3) Institute of Kinetics and Combustion Siberian Branch of Russian Academy of Sciences

(4) A.E. Favorsky Irkutsk Institute of Chemistry SB RAS

(5) Nikolaev Institute of Inorganic Chemistry Siberian Branch of Russian Academy of Sciences

(6) Novosibirsk State University

http://web.nioch.nsc.ru/nioch/en/

http://web.nioch.nsc.ru/nioch/en/

http://www.tomo.nsc.ru/

http://www.kinetics.nsc.ru/CMS/index.php?id=392

http://www.irkinstchem.ru/index.php/en/

http://store.niic.nsc.ru/en/

http://nsu.ru/?lang=en


8

General Information Registration and Welcome Reception: Registration and welcome reception will be held on Sunday 28

August from 9:00 to 20.00 in Mayak Hotel, Listvyanka, Irkutsk.

Mayak Hotel: 664520 Irkutsk region, Listvyanka, Gorky street, 85 A

tel.+7(3952) 496-910

web: http://mayakhotel.ru/en-main/

e-mail: [email protected]

Travel Information: Transportation from Airport (IKT) to the conference venue

Listvyanka (Hotel Mayak)

The airport of Irkutsk is located 10 kilometers away from Irkutsk city and ~70 kilometers away

from Listvyanka (Hotel Mayak).

Conference organizers will meet all participants in the arrival hall of the airport and assist them with

the transfer to Hotel. A few options are envisioned:

- personal taxi (price ca. 2000 rub./ 30 $)

- shared taxi (price divided for 3-4 people)

- shared minibus (price ca. 350 rub./ 6 $)

Please find us in the arrival hall by APES logo sign .

Depending on situation, we will match the best option for you.

In the case you cannot find any member of APES2016 Organizing Committee in the arrival hall of

the airport (there are two arrival halls: local and international; apparently we can be in another one

at the moment), please contact us by phones:

Sergey Veber: +7-913-734-00-85

Andrey Kuzhelev: +7-953-785-86-62

Ivan Timofeev: +7-983-130-20-15

For those participants who would like to reach Hotel by themselves, the following options are

recommended:

- x c “ ” ( : 8-3952-222-222, www.222222.ru) or other OFFICIAL taxi

services. It is strongly recommended to use only the OFFICIAL taxi services.

- N 4 4 43 f (“ ”) B (“ z ”)

then buses No 524 and 526 (available from 8.30 to 18.15) to the bus station Listvyanka (in the

close proximity of the hotel Mayak).

Transportation from Railway station to the conference venue v. Listvyanka (Hotel Mayak)

- x c “ ” ( : 8-3952-222-222, www.222222.ru) or other OFFICIAL

taxi services. It is strongly recommended to use only the OFFICIAL taxi services.

- Small bus N 4 f R (“z z z z ”) B

(“ z ”) N 5 4 and 526 (available from 8.30 to 18.15) to the bus

station Listvyanka (in the close proximity of the hotel Mayak).

http://www.222222.ru/

http://www.222222.ru/


9

Location of sessions: All scientific conference sessions will take place in Conference hall on the sixth floor of the hotel

“ ” P will take place in Restaurant on the second floor of the “ ”

Internet – WiFi: WiFi is available during the conference in the whole area Mayak Hotel. Hotel reception can give

you more detailed information about Wi-Fi and Password for access.

Presentation formats: The talks will be of the following lengths (including a few minutes for questions):

Plenary 40 min

Invited 30 min

Regular 20 min

Speakers: Speakers are asked to bring their presentation to the conference hall at least 15 min before the

session starts. Members of the local organization committee will be available to assist in

transferring presentation.

Prizes: Prizes for the best regular talk and poster prizes by International EPR Society will be awarded to

young scientists.

Excursion: After the lunch of Tuesday 30 August, will be Baikal sightseeing excursion for five hours from

Listvyanka to cape Tolstiy. Note that excursion is included in Registration fee.

Meals: The conference welcome party, banquet, breakfasts, lunches during the conference period will take

place in Restaurant on the second floor of the hotel “ ” C ff c

Panoramic grill-bar on the seventh floor of the “ ”

Other cafes are available within walking distance from Mayak hotel.

Contacts Prof. Elena Bagryanskaya – Chairperson

cell ph.: +7-913-794-50-58

Prof. Matvey Fedin – Co-chairman

cell ph.: +7-913-467-55-27

Dr. Dmitriy Polovyanenko – Secretary

cell ph.: +7-913-397-22-33

Dr. Sergey Veber – Transfer

cell ph.: +7-913-734-00-85

Web: www.apes2016.org e-mail: [email protected] tel: +7 (383) 330-96-61


10

Asia-Pacific EPR/ESR Symposium 2016 28 August – 02 September 2016

Lake Baikal, Irkutsk, Russia

Conference Program Sunday 28 August

9:00 – 20.00 Registration (Reception 1st floor)

18:00 – … Welcome Party (Restaurant 2nd

floor)

Monday 29 August

8:45 – 9:00 Conference Opening

(Conference hall 6th

floor)

Session 1 (Conference hall 6th

floor) Chair: Graham Smith

9:00 – 9:40

PL-01

Hitoshi Ohta

Kobe University, Kobe, Japan

Multi-Extreme THz ESR: New Developments and Applications

9:40 – 10:10

IN-01

Aharon Blank

Technion - Israel Institute of Technology, Haifa, Israel

ESR Sensitivity – Current Capabilities and Future Prospects and Applications

10:10 – 10:30

OR-01

Mark Tseytlin

West Virginia University, Morgantown, USA

Field Modulated Pulsed EPR

10:30 – 10:50

OR-02

Hideyuki Takahashi


Improved Setup for Force-Detected ESR Measurement using Fiber-Optic

Interferometry

10:50 – 11:20 Coffee Break (Grill-bar 7th

floor)


floor) Chair: Graham Smith

11:20 – 11:50

IN-02

Anton Savitsky

Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr,

Germany

ELDOR-Detected NMR: a Powerful EPR Technique for Hyperfine and Polarization

Transfer Studies

11:50 – 12:10

OR-03

Angeliki Giannoulis

University of St Andrews, St Andrews, Scotland, UK

Pulsed Dipolar EPR on Cu(II) and Co(II) Ions

12:10 – 12:30

OR-04

Seitaro Mitsudo

University of Fukui, Fukui, Japan

Application of Millimeter Wave Gyrotron to Pulsed ESR Measurements

12:30 – 12:50

OR-05

Igor Gromov

Bruker BioSpin GmbH, Rheinstetten, Germany

Improving Signal-to-Noise in EPR

12:50 – 14:30 Lunch / APES Council Meeting (Restaurant 2nd

floor)


floor) Chair: Elena Bagryanskaya

14:30 – 15:10

PL-02

Sergei Dzuba

Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, Novosibirsk,

Russia

New Approaches in Pulsed EPR for Studying Structure and Dynamics of Biological

Membranes


11

15:10 – 15:40

IN-03

Anatoly Vanin

Semenov Institute of Chemical Physics RAS, Moscow, Russia

EPR Discovery and Identification of Dinitrosyl Iron Complexes with Thiol-

Containing Ligands in Biological Objects

15:40 – 16:00

OR-06

Hiroyuki Mino

Nagoya University, Nagoya, Japan

Binding Structure of the Extrinsic Subunit PsbP of Photosystem II Revealed by

PELDOR

16:00 – 16:20

OR-07

Maxim Yulikov

Swiss Federal Institute of Technology in Zurich (ETH), Zürich, Switzerland

Trilateration and Orientation Selection DEER Measurements on Human Carbonic

Anhydrase Type II


floor)


floor) Chair: Elena Bagryanskaya

16:50 – 17:20

IN-04

Kiminori Maeda

Saitama University, Saitama, Japan

Spin Dynamics and Magnetic Field Effect in Flavin Containing Photochemical

Systems Studied by Static and Pulsed Magnetic Field

17:20 – 17:40

OR-08

Fumitoshi Ema


Electronic Structure of the Excited Triplet State of Hexaphyrins with twisted

Mobious Conformation as Studied by TR EPR

17:40 – 18:00

OR-09

Motoko Asano

Gunma University, Tokyo, Japan

Generation and Dissipation of Spin Polarization in the Excited Quartet State of

Vanadyl Porphyrins

18:00 – 18:20

OR-10

Yuri Kandrashkin

E. K. Zavoisky Kazan Physical-Technical Institute RAS, Kazan, Russia

Electron Spin Polarization Study of Charge Separated States in Molecular Triads

Centered by Aluminun Porphyrin

18:20 – … Poster Session / Snacks & Drinks (Restaurant 2nd

floor)

Tuesday 30 August

Session 5 (Conference hall 6

th floor) Chair: Sergei Dzuba

9:00 – 9:40

PL-03

Valery Khramtsov


Correlation of EPR-measured Tumor Microenvironment Parameters using

Multifunctional Trityl Probe

9:40 – 10:10

IN-05

Hiroshi Hirata

Hokkaido University, Sapporo, Japan

EPR-Based Oxygen-Sensitive Imaging using Isotopic Nitroxyl Radical

10:10 – 10:30

OR-11

Andrey Bobko


Overhauser DNP Properties of Phosphonated Trityl Probe: Dependence of Signal

Enhancement on Probe Exchange Parameters

10:30 – 10:50

OR-12

Elodie Parzy

University of Bordeaux, Bordeaux, France

In vivo Mapping of Protease Activity using Overhauser-enhanced MRI: Challenges

and Promises


12


floor)


floor) Chair: Sergei Dzuba

11:20 – 11:50

IN-06

Elena Bagryanskaya

N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk,

Russia

Distance Measurements in Nucleic Acids using Advanced SDSL with Nitroxyl and

Trityl Radicals

11:50 – 12:10

OR-13

Thilo Hetzke

Goethe University Frankfurt, Frankfurt am Main, Germany

Investigation of Tetracycline-binding RNA Aptamer by using ELDOR-detected

NMR

12:10 – 12:30

OR-14

Yuya Ishikawa

University of Fukui, Fukui, Japan

Development of High-Frequency Magnetic Resonance System for DNP

Measurements at very Low Temperatures

12:30 – 12:50

OR-15

Lu Yu

High Magnetic Field Lab, Chinese Academy of Sciences, Hefei, China

Using SDSL-EPR Spectroscopy to Characterize the Structural Details of Membrane

Proteins

12:50 – 14:30 Lunch (Restaurant 2nd

floor)

14:30 – 20:00 Baikal Sightseeing Excursion

Wednesday 31 August


floor) Chair: Daniella Goldfarb

9:00 – 9:40

PL-04

Gunnar Jeschke

Swiss Federal Institute of Technology in Zurich (ETH), Zürich, Switzerland

Ultra-Wideband Pulse EPR Spectroscopy

9:40 – 10:10

IN-07

Alexey Semenov

Moscow State University, Moscow, Russia

Effect of Dehydrated Trehalose Matrix on the Kinetics of forward Electron Transfer

Reactions in Photosystem I

10:10 – 10:30

OR-16

Balachandra Hegde

Rani Channamma University, Belagavi, India

EPR Investigation of Conformational Changes in Annexin 12 upon Membrane

Interaction

10:30 – 10:50

OR-17

Daniel Häussinger

University of Basel, Basel, Switzerland

In-cell Protein Structures from Single 2D-NMR Experiments using Lanthanide

Chelating Tags Suitable for PCS-NMR and EPR Studies


floor)


floor) Chair: Daniella Goldfarb

11:20 – 11:50

IN-08

Tomoaki Miura

Niigata University, Niigata, Japan

Recent Development in Spin Chemistry of Photo-Generated Radical Pairs Confined

in Surfactant-Based Soft Nanomaterials

11:50 – 12:10

OR-18

Spartak Khutsishvili

A.E. Favorsky Irkutsk Institute of Chemistry SB RAS, Irkutsk, Russia

Humic Substances as Matrixes for Obtaining of the Silver-Containing

Bionanocomposites with Antioxidant Activity


13

12:10 – 12:30

OR-19

Nikolay Tikhonov

A.E. Favorsky Irkutsk Institute of Chemistry SB RAS, Irkutsk, Russia

Magnetic Nanoparticles Reorganization in Ferroarabinogalctain in The Process of

Thermal Degradation

12:30 – 12:50

OR-20

Ruslan Zaripov


Investigation of hyperfine interaction in Cu(II)-bis(oxamidato) complexes by pulse

ED NMR technique


floor)


floor) Chair: Valery Khramtsov

14:30 – 15:10

PL-05

Steven Bottle

Queensland University of Technology, Brisbane, Australia

Following the Fate of Free Radicals Using EPR and Fluorescence

15:10 – 15:40

IN-09

Igor Kirilyuk


Russia

Sterically Shielded Nitroxides: Advanced Spin Labels with High Stability to

Reduction

15:40 – 16:00

OR-21

Kouichi Nakagawa

Hirosaki University, Hirosaki, Japan

Distribution of Stable Paramagnetic Species in Apple Seeds Investigated by EPR

and X-band EPR Imaging

16:00 – 16:20

OR-22

Sylvain Marque

Aix-Marseille University, Marseille, France


Russia

Enzymatically Activated Nitroxides for EPR spectroscopy and Overhauser-

enhanced Magnetic Resonance Imaging (OMRI)


floor)


floor) Chair: Jiangfeng Du

16:50 – 17:20

IN-10

Yong Li

Tsinghua University, Beijing, China

EPR Studies on Mechanism of Copper Catalyzed Aerobic Reaction

17:20 – 17:40

OR-23

Roman Kenzhin

Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia

EPR Characterization of Surface Electron-Donor Sites of Pd-Rh/Alumina Three-

Way Catalysts

17:40 – 18:00

OR-24

Haijun Yang

Tsinghua University, Beijing, China

Mechanism Study of Functionalization of Aryl Halides via Visible Light Catalyst

18:00 – 18:20

OR-25

Matvey Fedin

International Tomography Center SB RAS, Novosibirsk, Russia

EPR Study of the MOF-based Photocatalytic System Co@NH2-MIL-125(Ti)

18:20 – … Poster Session / Snacks & Drinks (Restaurant 2nd

floor)


14

Thursday 1 September


th floor) Chair: Susumu Takahashi

9:00 – 9:40

PL-06

Jiangfeng Du

University of Science and Technology of China, Hefei, China

Quantum Control of Spins in Solids and its Applications

9:40 – 10:10

IN-11

Vladimir Nadolinny

Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, Russia

Peculiarities of Ni, Co, P, Si and Ge Split-Vacancy Defects Formation in Diamond.

Magnetic and Optical Properties of the Split-Vacancy Defects

10:10 – 10:30

OR-26

Fazhan Shi


Single Molecule Electron Spin Resonance Spectroscopy by Diamond Sensor

10:30 – 10:50

OR-27

Xing Rong


Precise Quantum Control of Spins in Solids


floor)


th floor) Chair: Matvey Fedin

11:20 – 11:50

IN-12

Susumu Takahashi

University of Southern California, Los Angeles, USA

Electron Spin Resonance Spectroscopy using NV Centers in Diamond

11:50 – 12:10

OR-28

Toshikazu Nakamura

Institute for Molecular Science, Okazaki, Japan

Curious Electronic Phases and ESR Behaviors in One-Dimensional Organic

Conductors (TMTCF)2X

12:10 – 12:30

OR-29

Gerd Kothe

University of Freiburg, Freiburg, Germany

Light-induced Generation of Entangled Nuclear Spin Qubits in Molecular Crystals

12:30 – 12:50

OR-30

Artem Poryvaev


Mobility and Reactivity of 4-substituted TEMPO Derivatives in Metal-Organic

Framework MIL-53(Al)


floor)


floor) Chair: Gunnar Jeschke

14:30 – 15:10

PL-07

Daniella Goldfarb

Weizmann Institute of Science, Rehovot, Israel

ATPase Mechanism of ABC Exporters and RNA Helicases Explored by Time

Resolved High Field Hyperfine Spectroscopy

15:10 – 15:40

OR-31

Hiroki Nagashima

Nagoya University, Nagoya, Japan

Proton Matrix ENDOR Study on the Structure of Ca2+

-Depleted and NH3-Binding

Mn Cluster in Photosystem II

15:40 – 16:00

OR-32

Mizue Asada

Institute for Molecular Science, Okazaki, Japan

PELDOR Stydy on the High-Affinity Mn2+

Site of the Photoactivation of the

Oxygen-Evolving Complex in Photosystem II


15

16:00 – 16:20

OR-33

Andrei Kuzhelev


Russia

Saccharides as Prospective Immobilizers of Nucleic Acids for Room-Temperature

Structural EPR Studies


floor)


floor) Chair: Gunnar Jeschke

16:50 – 17:20

OR-34

Victoria Syryamina


Russia

ESEEM Study of Molecular Motions of Deuterated Molecules nearby the spin Label

17:20 – 18:20 APES General Meeting (Conference hall 6th

floor)

18:20 – … Banquet (Restaurant 2nd

floor)

Friday 2 September


floor) Chair: Subray Bhat

9:00 – 9:40

PL-08

Graham Smith

University of St Andrews, St Andrews, Scotland, United Kingdom

What are the Concentration Sensitivity and Time Resolution Limits for Pulsed EPR?

9:40 – 10:10

IN-13

Czeslaw Rudowicz

West Pomeranian University of Technology, Szczecin, Poland

Huge (Giant) Magnetic Anisotropy in Nickel(II) Complexes Revisited -

Semiempirical Versus ab initio Modeling of Zero-Field Splitting

10:10 – 10:30

OR-35

Nina Gritsan


Russia

Electronic Structure and Properties of New Nitronyl and Imino Nitroxide Diradicals:

DFT and ab initio Study

10:30 – 10:50

OR-36

Mikhail Ivanov


Microstructuing of Ionic Liquids Studied by Time-Resolved EPR of Photoexcited

Triplets


floor)


th floor) Chair: Subray Bhat

11:20 – 11:50

IN-14

Christopher Ambe

Mindanao State University, Iligan City, Philippines

Magnetic Field Effect on the Photocarrier Dynamics in Perylene Bisimide

Derivative: An Experimental and Computational Study

11:50 – 12:10

OR-37

Alena Sheveleva


Continuous Wave and Time-Resolved EPR Study of Photoinduced Radicals in

Fluoroacrylic Porous Polymer Films

12:10 – 12:30

OR-38

Ekaterina Lukina


Russia

Light-Induced Charge Transfer State in P3HT/PC70BM Composite as Studied by

Out-of-Phase Electron Spin Echo Spectroscopy


16

12:30 – 12:50

OR-39

Egor Nasibulov


Theoretical treatment of pulsed Overhauser DNP


floor)


floor) Chair: Hitoshi Ohta

14:30 – 15:10

PL-09

Subray Bhat

Indian Institute of Science, Banglore, India

Fascinating Phase Diagrams of Doped Rare-Earth Manganites: Insights from

Electron Magnetic Resonance and Magnetization Studies

15:10 – 15:40

IN-15

Tadaaki Ikoma

Niigata University, Niigata, Japan

Excited Triplet States of Thermally Activated Delayed Fluorescent Molecules

15:40 – 16:00

OR-40

Ramakrishna Damle

Bangalore University, Bangalore, India

EPR and Magnetic Studies of Bi0.5Sr0.5Mn0.9Cr0.1O3

16:00 – 16:20

OR-41

Andrey Sukhanov


CW Time-Resolved and Pulse EPR Investigations of Photoinduced Spin States of

Metalloporphyrin Derivatives Systems


floor)


floor) Chair: Hitoshi Ohta

16:50 – 17:20

OR-42

Sergey Veber


Multifrequency EPR of Thermo- and Photoswitchable Copper-Nitroxide-Based

Molecular Magnets

17:20 – 18:00 Closing (Conference hall 6th

floor)

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17

TABLE OF CONTENTS

Multi-extreme THz ESR: New developments and applications Hitoshi Ohta, Susumu Okubo, Eiji Ohmichi, Takahiro Sakurai, Hideyuki Takahashi ......................... 25

New Approaches in Pulsed EPR for Studying Structure and Dynamics of Lipid Membranes S.A. Dzuba ........................................................................................................................................................ 26

Correlation of EPR-measured Tumor Microenvironment Parameters using Multifunctional Trityl Probe

Valery V. Khramtsov, Andrey A. Bobko, Benoit Driesschaert, Ilirian Dhimitruka, Jason Evans, Mikhail M. Dikov and Timothy D. Eubank.................................................................................................. 27

Ultra-wideband pulse EPR spectroscopy Andrin Doll, Takuya Segawa, Stephan Pribitzer, Frauke Breitgoff, Yevhen Polyhach, Gunnar Jeschke ............................................................................................................. 28

Following the Fate of Free Radicals Using EPR and Fluorescence Steven Bottle, James Blinco and Liam Walsh ............................................................................................. 29

Quantum control of spins in solids and its applications Jiangfeng Du .................................................................................................................................................... 30

ATPase mechanism of ABC exporters and RNA helicases explored by time resolved high field hyperfine spectroscopy

A. Collauto, S. Mishra, M. Bye, H. S. Mchaourab, D. Goldfarb ............................................................. 31

What are the concentration sensitivity and time resolution limits for pulsed EPR? G.M. Smith, C. Motion, J. McKay, R.I. Hunter, D.R .Bolton, H. El Mkami ......................................... 32

Fascinating phase diagrams of doped rare-earth manganites: insights from electron magnetic resonance and magnetization studies

S.V. Bhat, K.S. Bhagyashree ......................................................................................................................... 33

Molecular Lanthanide Spin Qubits Stephen Hill, Dorsa Komijani, Muhandis Shiddiq, Yan Duan, Alejandro Gaita-Ariño, Alberto Ghirri, Marco Affronte, Eugenio Coronado............................................................................ 34

ESR sensitivity – current capabilities and future prospects and applications Aharon Blank .................................................................................................................................................. 35

ELDOR-detected NMR: a powerful EPR technique for hyperfine and polarization transfer studies

Anton Savitsky ................................................................................................................................................ 36

Discovery and Identification of Dinitrosyl Iron Complexes with Thiol-containing Ligands in Biological Objects by the EPR Method

Anatoly F. Vanin ............................................................................................................................................ 37

Spin dynamics and Magnetic Field Effect in Flavin containing photochemical systems studied by static and pulsed magnetic field

Kiminori Maeda ............................................................................................................................................. 38

Development of a CW-EPR-based oxygen-mapping technique using a pair of isotopic nitroxyl radicals

H. Hirata, H. Kubota, H. Yasui, S. Matsumoto, O. Inanami, I.A. Kirilyuk and V.V. Khramtsov ...... 39


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Distance Measurements in Nucleic Acids using Advanced SDSL with Nitroxyl and Trityl Radicals Elena Bagryanskaya, Olesya Krumkacheva, Matvei Fedin, Andrei Kuzhelev, Victor Tormyshev, Igor Kirilyuk, Elena Babaylova, Galina Karpova, Georgy Shevelev, Dmitry Pyshny ........................... 40

Effect of dehydrated trehalose matrix on the kinetics of forward electron transfer reactions in Photosystem I

Alexey Yu. Semenov, Ivan V. Shelaev, Michael Gorka, Anton Savitsky, Vasily Kurashov, Mahir D. Mamedov, Fedor E. Gostev, Klaus Möbius, Victor A. Nadtochenko, John Golbeck ............ 41

Recent development in spin chemistry of photo-generated radical pairs confined in surfactant-based soft nanomaterials

Tomoaki Miura, Kiminori Maeda, Hisao Murai and Tadaaki Ikoma ..................................................... 42

Sterically shielded nitroxides: advanced spin labels with high stability to reduction Sergey A. Dobrynin, Natalia M. Kuprikova, Denis A. Morozov, Yuliya F. Polienko, Irina F. Zhurko, and Igor A. Kirilyuk .......................................................................................................... 43

EPR Studies on Mechanism of Copper Catalyzed Aerobic Reaction Yong Li, Min Jiang, Haijun Yang ................................................................................................................. 44

Peculiarities of Ni, Co, P, Si and Ge split-vacancy defects formation in diamond. Magnetic and optical properties of the split-vacancy defects

V.A. Nadolinny, A.Yu. Komarovskikh, Yu.N. Palyanov .......................................................................... 45

Electron spin resonance spectroscopy using NV centers in diamond Susumu Takahashi ......................................................................................................................................... 46

Huge (giant) magnetic anisotropy in nickel(II) complexes revisited - semiempirical versus ab initio modeling of zero-field splitting

Czesław Rudowicz, Muhammed Açıkgöz and Paweł Gnutek .................................................................. 47

Magnetic Field Effect on the Photocarrier Dynamics in Swallow-Tailed Perylene Bisimide Derivative: Experimental and Computational Studies

Christopher Ambe, Yusuke Wakikawa, Shiki Yagai, Tadaaki Ikoma ................................................... 49

Excited Triplet States of Some Molecules Showing Thermally Activated Delayed Fluorescence Tadaaki Ikoma ................................................................................................................................................ 50

EPR-active molecular pH probes at a protein-lipid interface: an assessment of local electrostatic effects

Tatyana I. Smirnova, Matthew Donohue, Maxim A. Voynov, Alex I. Smirnov .................................. 51

Combining Spin-labeling EPR, Solid-state NMR and Site-directed DNP for Structure Determination of Oligomeric Proteins in Lipid Bilayer Membranes

Sergey Milikisiyants, Maxim A. Voynov, Shenlin Wang, Rachel Munro, Matthew Donohue, Leonid S. Brown, Tatyana I. Smirnova, Vladimir Ladizhansky, Alex I. Smirnov ................................ 52

Field modulated pulsed EPR Mark Tseytlin, Boris Epel, Subramanian Sundramoorthy, Dmitriy Tipikin, and Howard J. Halpern ...................................................................................................... 53

Improved setup for force-detected ESR measurement using fiber-optic interferometry Hideyuki Takahashi, Tsubasa Okamoto, Eiji Ohmichi and Hitoshi Ohta ............................................. 54

Pulsed Dipolar EPR on Cu(II) and Co(II) ions Angeliki Giannoulis, Katrin Ackermann and Bela E. Bode ..................................................................... 55


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Application of millimeter wave gyrotron to pulsed ESR measurement S. Mitsudo, K. Hiiragi, M. Narioka, C. Umegaki, Y. Fujii ....................................................................... 56

Improving Signal-to-Noise in EPR Igor Gromov and Peter Höfer ....................................................................................................................... 57

Binding structure of the extrinsic subunit PsbP of photosystem II revealed by PELDOR Hiroyuki Mino, Mizue Asada, Taishi Nishimura, Fumihiko Sato, Kentaro Ifuku ................................ 58

Trilateration and orientation selection DEER measurements on human carbonic anhydrase type II

Maxim Yulikov, Luca Garbuio, Kaspar Zimmermann, Elisa Nogueira, Guido Grassi, Thomas R. Ward, Daniel Häussinger, Gunnar Jeschke .............................................................................. 59

Electronic Structure of the Excited Triplet State of Hexaphyrins with twisted Möbius Conformation As Studied by Time-resolved EPR

Fumitoshi Ema, Shohei Saito, Atsuhiro Osuka, Mana Tanabe, Seigo Yamauchi, Kenji Sugisaki, Kazunobu Sato, Takeji Takui, Takashi Tachikawa, Yasuhiro Kobori...................................................... 60

Generation and Dissipation of Spin Polarization in the Excited Quartet State of Vanadyl Porphyrins

Motoko S. Asano, Tsubasa Asami, Yoshifumi Yasuda and Art van der Est .......................................... 61

Electron Spin Polarization Study of Charge Separated States in Molecular Triads Centered by Aluminum Porphyrin

Yuri E. Kandrashkin, Prashanth K. Poddutoori and Art van der Est ..................................................... 62

Overhauser DNP properties of phosphonated trityl probe: dependence of signal enhancement on probe exchange parameters

Andrey A. Bobko, Benoit Driesschaert, Valery V. Khramtsov................................................................ 63

In vivo mapping of protease activity using Overhauser-enhanced MRI: challenges and promises Gérard Audran, Paul Brémond, Jean-Michel Franconi, Neha Koonjoo, Sylvain Marque, Philippe Massot, Philippe Mellet, Elodie Parzy, Eric Thiaudière ........................................................... 64

Investigation of a Tetracycline-binding RNA aptamer by using ELDOR-detected NMR Thilo Hetzke, Alice Bowen, Marc Vogel, Beatrix Suess, Thomas Prisner ............................................. 65

Development of High-Frequency Magnetic Resonance System for DNP Measurements at Very Low Temperatures

Y. Ishikawa, K. Ohya, S. Miura, Y. Fujii, S. Mitsudo, T. Mizusaki, H. Kikuchi, A. Fukuda, A. Matsubara, S. Lee, H. Yamamori and S. Vasiliev .................................................................................. 66

Using SDSL-EPR spectroscopy to characterize the structural details of membrane proteins Lu Yu, Li Zhou, Ying Xiong, Changlin Tian .............................................................................................. 67

EPR Investigation of Conformational Changes in Annexin 12 upon Membrane Interaction Balachandra G. Hegde and Ralf Langen .................................................................................................... 68

In-cell protein structures from single 2D-NMR experiments using lanthanide chelating tags suitable for PCS-NMR and EPR studies

Daniel Häussinger, Thomas Müntener, Francois-Xavier Theillet, Philipp Selenko, Maxim Yulikov, Gunnar Jeschke ................................................................................................................... 69


20

Humic Substances as Matrixes for Obtaining of The Silver-Containing Bionanocomposites with Antioxidant Activity

Spartak S. Khutsishvili, Nikolay I. Tikhonov, Marina V. Lesnichaya, G. Dolmaa, Tamara I. Vakul’skaya, Galina P. Aleksandrova, Boris G. Sukhov.......................................................... 70

Magnetite Nanoparticles Reorganization in Ferroarabinogalactan in The Process of Thermal Degradation

Nikolay I. Tikhonov, Spartak S. Khutsishvili, Tamara I. Vakul’skaya, Galina P. Aleksandrova, Boris G. Sukhov ............................................................................................................................................... 71

Investigation of hyperfine interaction in Cu(II)-bis(oxamidato) complexes by pulse ED NMR technique R.B.Zaripov, E.L.Vavilova, V. K. Voronkova, K.M. Salikhov, A. Aliabadi, A. Petr, V. Kataev, B. Büchner, M. A. Abdulmalic, T. Rüffer.......................................................................72 Magnetic properties of YMnO3 ceramic samples

Rushana M. Eremina, Ivan V. Yatsyk, Tatiana P. Gavrilova, Ildar F. Gilmutdinov, Vladimir I. Chichkov, Nikolai V. Andreev................................................................................................. 72B

Distribution of Stable Paramagnetic Species in Apple Seeds Investigated by EPR and X-band EPR Imaging

Kouichi Nakagawa and Boris Epel .............................................................................................................. 73

Solvent effect in Nitroxides: What’s New in 2016 G. Audran, P. Brémond, S.R.A. Marque ..................................................................................................... 74

EPR Characterization of Surface Electron-Donor Sites of Pd-Rh/Alumina Three-Way Catalysts Roman M. Kenzhin, Alexander M. Volodin, Vladimir O. Stoyanovskii, Aleksey A. Vedyagin, Ilya V. Mishakov............................................................................................................................75 EPR Characterization of Surface Electron-Acceptor Sites during Catalytic and Solid-State Reactions

Alexander Bedilo, Ekaterina Shuvarakova, Alexander Volodin ............................................................ 75B

Mechanism Study of Functionalization of Aryl Halides via Visible Light Catalyst Haijun Yang, Min Jiang, Yong Li ................................................................................................................ 76

EPR study of the MOF-based photocatalytic system Co@NH2-MIL-125(Ti) M.V. Fedin, S.L. Veber, D. Yu. Osadchii, M.A. Nasalevich, R. Becker, E.V. Ramos-Fernandez, S. Castellanos, F. Kapteijn, J.N.H. Reek, J.I. van der Vlugt, J. Gascon ........................................................ 77

Single-molecule Electron Spin Resonance spectroscopy by diamond sensor Fazhan Shi ........................................................................................................................................................ 78

Precise quantum control of spins in solids Xing Rong, Jianpei Geng, Fazhan Shi, Jiangfeng Du ................................................................................ 79

Curious Electronic Phases and ESR Behaviors in One-Dimensional Organic Conductors (TMTCF)2X

Mizue Asada and Toshikazu Nakamura .................................................................................................... 80

Light-induced Generation of Entangled Nuclear Spin Qubits in Molecular Crystals Gerd Kothe, Michail Lukaschek, Tomoaki Yago, Gerhard Link, Konstantin L. Ivanov and Tien-Sung Lin ..................................................................................................... 81

Mobility and Reactivity of 4-Substituted TEMPO Derivatives in Metal-Organic Framework MIL-53(Al) Artem Poryvaev, Alena Sheveleva, Daniil Kolokolov, Alexander Stepanov, Matvey Fedin, Elena Bagryanskaya .............................................................................................................. 82


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Proton matrix ENDOR study on the structure of Ca2+-depleted and NH3-binding Mn cluster in photosystem II

Hiroki Nagashima and Hiroyuki Mino........................................................................................................ 83

PELDOR study on the high-affinity Mn2+ site of the photoactivation of the oxygen-evolving complex in photosystem II

Mizue Asada, Hiroyuki Mino ........................................................................................................................ 84

Saccharides as Prospective Immobilizers of Nucleic Acids for Room-Temperature Structural EPR Studies

Andrei Kuzhelev, Georgiy Shevelev, Olesya Krumkacheva, Victor Tormyshev, Dmitrii Pyshnyi, Matvey Fedin, Elena Bagryanskaya ................................................................................ 85

ESEEM Study of Molecular Motions of Deuterated Molecules nearby the Spin Label Victoria Syryamina, Alexander Maryasov, Michael Bowman, Sergey Dzuba ..................................... 86

Electronic Structure and Properties of New Nitronyl and Imino Nitroxide Diradicals: DFT and ab initio Study

Dmitry E. Gorbunov, Evgeny V. Tretyakov, Nina P. Gritsan ................................................................. 87

Microstructuring of ionic liquids studied by time-resolved EPR of photoexcited triplets Mikhail Ivanov, Sergey Veber, Sergey Prikhod’ko, Nikolay Adonin, Elena Bagryanskaya, Matvey Fedin .............................................................................................................. 88

Continuous Wave and Time-Resolved EPR Study of Photoinduced Radicals in Fluoroacrylic Porous Polymer Films

A.M. Sheveleva, M.Yu. Ivanov, S.L. Veber, I.K. Shundrina, V.V. Shelkovnikov, E.G. Bagryanskaya, M.V. Fedin .................................................................................................................... 89

Light-Induced Charge Transfer State in P3HT/PC70BM Composite as Studied by Out-of-Phase Electron Spin Echo Spectroscopy

E.A. Lukina, A.A. Popov and L.V. Kulik ................................................................................................... 90

Theoretical treatment of pulsed Overhauser DNP Egor A. Nasibulov, Alexey S. Kiryutin, Alexandra V. Yurkovskaya, Hans-Martin Vieth, and Konstantin L. Ivanov...............................................................................91 Characterization of Mn2+ doped PbS nanocrystals using various techniques

Ram Kripal, Upendra M. Tripathi ............................................................................................................ 91B

EPR and Magnetic Studies of Bi0.5Sr0.5Mn0.9Cr0.1O3 K.S. Bhagyashree, R. Damle and S.V. Bhat ................................................................................................ 92

CW Time-Resolved and pulse EPR investigations of photoinduced spin states of metalloporphyrin derivatives systems

Andrey Sukhanov, Violeta Voronkova, Vladimir Tyurin ........................................................................ 93

Multifrequency EPR of thermo- and photoswitchable copper-nitroxide-based molecular magnets Sergey L. Veber, Matvey V. Fedin, Elena G. Bagryanskaya and Victor I. Ovcharenko ...................... 94

Alamethicin-Induced Homogenization of Model Biological Membrane by Pulse EPR Ekaterina Afanasyeva, Victoria Syryamina, Nikolay Isaev,

Sergei Dzuba .......................................... 95

Highly sensitive measurement of MFE for probing electron spin dynamics of intermediate biradical in flavin adenine dinucleotide

Kazuya Arakawa, Kiminori Maeda, Jonathan R. Woodward .................................................................. 96


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Portable Coherent Superheterodyne X-band EPR Spectrometer Alexander Rokeakh, Mikhail Artyomov ..................................................................................................... 97

Spin Probe ESR Detected Dynamics of Interstitial Supercooled Water Debamalya Banerjee, S.N. Bhat, S.V. Bhat and Dino Leporini .............................................................. 98

Magnetic behavior peculiarities of heterometallic Cu-Pb complex Alexey S. Berezin, Vladimir A. Nadolinny, Vladislav V. Krisyuk .......................................................... 99

Singly-Bonded [60]Fullerene Dimers Studied by in situ EPR Spectroscopy Wenqi Liu, Jiafu Chen and Jihu Su ............................................................................................................ 100

EPR and optical absorption studies of Cr3+ doped cesium tetrabromozincate Ram Kripal, Awadhesh Kumar Yadav and Prashant Dwivedi .............................................................. 101

Trityl-based alkoxyamines: C—ON bond homolysis for potential NMP controllers and spin-labels Gérard Audran, Elena G. Bagryanskaya, Paul Brémond, Mariya Edeleva, Sylvain R. A. Marque, Dmitriy Parkhomenko, Olga Yu. Rogozhnikova, Victor M. Tormyshev, Evgeny Tretyakov, Dmitry V. Trukhin, and Svetlana Zhivetyeva ............................................................................................ 102

Electron paramagnetic resonance of 157Eu2+-doped yttrium aluminum garnet A.V. Fokin, V.A. Vazhenin, A.P. Potapov, M.Yu. Artyomov, H.R. Asatryan, A.G. Petrosyan and K.L. Ovanesyan .............................................................................................................................................. 103

Low-Temperature Dynamical Transition in Lysozyme by Pulsed EPR of Spin Labels E.A. Golysheva, S.A. Dzuba ....................................................................................................................... 104

Investigation of Grain Size Effect on the Properties of Sm0.08Ca0.92MnO3 Lora Rita Goveas, K.N. Anuradha and S.V. Bhat.................................................................................... 105

On-line Detection of Antioxidant Ability by LC-ESR-MS Hideyuki Hara, Haruo Hosoda ................................................................................................................... 106

One-electron electrochemical oxidation and reduction of the first C(sp2)-coupled nitronyl nitroxide diradical

L.A. Shundrin, I.G. Irtegova, N.V. Vasilieva, E.V. Tretyakov, E.M. Zueva, V.I. Ovcharenko ........ 107

X-band bismuth germanate dielectric resonator Mikhail Ivanov, Sergey Veber, Elena Bagryanskaya, Matvey Fedin, Vladimir Nadolinniy, Gennady Kuznetsov ....................................................................................................................................... 108

Assemblies of spin-labeled molecules in model lipid membranes by pulsed EPR Maria Kardash, Sergei Dzuba .................................................................................................................... 109

EPR of germanium-vacancy defect in diamond A.Y. Komarovskikh, V.A. Nadolinny, Y.N. Palyanov, I.N. Kupriyanov, O.P. Yuryeva, M.I. Rakhmanova ................................................................................................................ 110

High-frequency EPR data for Fe2+ and Cr2+ spin S = 2 ions in natural and synthetic forsterite revisited: effective S~ = 2 vs fictitious S' = 1 approach

M. Kozanecki, C. Rudowicz ........................................................................................................................ 111

EPR and optical Spectroscopy of transition and rare-earth ions doped systems Ram Kripal .................................................................................................................................................... 112


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Distance Measurements in Hepatitis C Virus RNA Internal Ribosome Entry Site and Human Ribosomes Olesya A. Krumkacheva, Elena S. Babaylova, Alexey A. Malygin, Alexander A. Lomzov, Dmitrii V. Pyshnyi, Matvey V. Fedin, Maxim M. Yulikov, Gunnar Jeschke, Galina G. Karpova and Elena G. Bagryanskaya..........................................................................113 Triarylmethyl Radicals: EPR Study of 13C Hyperfine Coupling Constants

Andrey Kuzhelev, Victor Tormyshev, Olga Rogozhnikova, Dmitry Trukhin, Tatiana Troitskaya, Rodion Strizhakov, Olesya Krumkacheva, Matvey Fedin, Elena Bagryanskaya ............................. 113B

Study of Nitroxide Relaxation in Glassy Trehalose for Room-Temperature Pulsed EPR Distance Measurements

Andrey Kuzhelev, Rodion Strizhakov, Olesya Krumkacheva,Yuliya Polienko, Denis Morozov, Georgiy Shevelev, Dmitrii V. Pyshnyi, Igor Kirilyuk, Matvey Fedin, Elena Bagryanskaya .............. 114

Triarylmethyl Radicals: Study of Room-Temperature Relaxation Properties at the X- and Q- Bands

Andrey Kuzhelev, Dmitry Trukhin, Olesya Krumkacheva, Rodion Strizhakov, Olga Rogozhnikova, Tatiana Troitskaya, Matvey Fedin, Victor Tormyshev, Elena Bagryanskaya ........................................ 115

Photosensitive NO-releasing Ruthenium Complexes Minyeong Kim and Hong-In Lee ................................................................................................................ 116

EPR line widths of magnetically concentrated rare-earth compounds: a theoretical calculation for crystal with low symmetry

Hong-Gang Liu and Wen-Chen Zheng ...................................................................................................... 117

The Absorption Tendency of Mugieic Acid on Soil Mineral in Amagatsuji Area, Nara Yuki Matsuoka .............................................................................................................................................. 118

PELDOR Analysis of Biradical Conformations Basing on Monte Carlo Solution of the Reverse Problem Anna Matveeva, Sergei Dzuba ................................................................................................................... 119

Skin surface imaging of psoriasis vulgaris investigated by X-band EPR Kouichi Nakagawa, Satoko Minakawa, Daisuke Sawamura, Hideyuki Hara ..................................... 120

Theoretical treatment of pulsed Overhauser DNP Egor A. Nasibulov, Alexey S. Kiryutin, Alexandra V. Yurkovskaya, Hans-Martin Vieth and Konstantin L. Ivanov ..................................................................................................................................... 121

Force-detected ESR measurements in a terahertz range up to 0.4 THz T. Okamoto, H. Takahashi, E. Ohmichi and H. Ohta .............................................................................. 122

Terahertz ESR Measurements Susumu Okubo, So Kubota, Yoko Kitahara, Shigeo Hara, Takahiro Sakurai, Hitoshi Ohta, Daichi Yoshizawa, Masayuki Hagiwara, Fumiko Kimura, Tsunehisa Kimura, Kazuhiro Nawa, Yoshihiko Okamoto, Zenji Hiroi ................................................................................................................. 123

Investigation of guest−host interaction under gas sorption in the Zn2-x(Cu)x(bdc)2(DABCO) with EPR spectroscopy

Artem Poryvaev, Alena Sheveleva, Danil Dybtsev, Pavel Demakov, Matvey Fedin......................... 124

Magnetic properties of Cu1.8Mn1.2BO5 crystal Rushana M. Eremina, Ivan V. Yatsyk, Evgeniya M. Moshkina, Mikhail V. Rautskii, Leonard N. Bezmaternykh, Hans-Albrecht Krug von Nidda, Alois Liodl ............................................. 125


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Continuous Wave and Pulse EPR study of gas sorption in ZIF-8 A.M. Sheveleva, A.S. Poryvaev, M.V. Fedin ........................................................................................... 126

Electrochemical oxidation, reduction and radical anions of 2-substituted thioxanthone-9-ones, their S-oxide derivatives and thioxanthenetrions

L.A. Shundrin, I.G. Irtegova, V.A. Loskutov, N.V. Vasilieva ............................................................... 127

Characterization of pure and manganese doped TiO2 nanoparticles Ram Kripal, Vini Singh ................................................................................................................................ 128

Peptides on the Surface. The Multi-Conformity of Trichogin GA IV and Ampullosporin A on the Silica Nanoparticles by Pulse and CW EPR

Victoria Syryamina, Rimma Samoilova, Yuri Tsvetkov, Fernando Formaggio, Sergey Dzuba .................................................................................................................................................. 129

Dynamic Electron Polarization Created by the Interaction between Singlet Oxygen and Trityl Radical

Hirona Takahashi, Toshiro Tamura, Mai Kato, Valery Khramtsov, Akio Kawai .............................. 130

EPR Study of the Mobility of Spin Labels attached to a dsDNA Ivan Timofeev, Andrei Kuzhelev, Olesya Krumkacheva, Matvey Fedin, Elena Bagryanskaya ....... 131

EPR study of intra- and intermolecular exchange interactions in [Cu(hfac)2LEt]2 compound Sergey Tumanov, Irina Obsharova, Svyatoslav Tolstikov, Victor Ovcharenko, Matvey Fedin, Sergey Veber ........................................................................................................................ 132

Comparative study of EPR, structural and optical properties of CdS, TiO2 nanoparticles and CdS@TiO2 core-shell nanocomposite

Ram Kripal, Garima Vaish .......................................................................................................................... 133

Magnetic Properties of CoII with Large ZFS: Experimental and Computational Study J. Nehrkorn, Sergey L. Veber, E.A. Suturina, L.A. Zhukas, I. Fomina, A. Belov, E. Colacio, E.V. Fursova, P. Cucos, M. Andruh, J. Krzystek, S. Stoll, K. Holldackand A. Schnegg .................... 134

EPR and optical absorption study of Fe3+ doped mono hydrated Dipotassium Stannic chloride Ram Kripal and Awadhesh Kumar Yadav ............................................................................................... 135

Zero-Field Splitting and Its Temperature Dependence in a High-Spin Co(I) Clathrochelate Studied by FD-FT THz-EPR Spectroscopy

Joscha Nehrkorn, Sergey L. Veber, Liudmila A. Zhukas, Valentin V. Novikov, Yulia V. Nelyubina, Yan Z. Voloshin, Karsten Holldack, Stefan Stoll and Alexander Schnegg ........................................... 136

AUTHOR INDEX ........................................................................................................................ 137

PLENARY


25

Multi-extreme THz ESR: New developments and applications

Hitoshi Ohta,1,2

Susumu Okubo,1 Eiji Ohmichi,

2 Takahiro Sakurai,

3 Hideyuki Takahashi

4

1 Molecular Photoscience Research Center, Kobe University, Kobe, 657-8501 Japan

2 Graduate School of Science, Kobe University, Kobe, 657-8501, Japan

3 Center for Support to Research and Education Activities, Kobe University, Kobe, 657-8501, Japan

4 Organization of Advanced Science and Technology, Kobe University, Kobe, 657-8501, Japan

E-mail: [email protected]

Recent developments and applications of our multi-extreme THz ESR will be presented. The

specifications of our multi-extreme THz ESR are the followings.

Frequency region from 0.03 to 7 THz using Gunn oscillators, multipliers, backward wave

oscillators (BWO), and optically pumped far infrared laser [1].

Temperature region from 1.8 to 300 K.

High magnetic field up to 55 T using the pulsed magnetic field driven by the capacitor bank

with the pulse duration of about 10 msec [1].

High pressure up to 1.5 GPa and 2.7 GPa using the transmission type piston cylinder pressure

cell [2] and the transmission type hybrid-type pressure cell [3].

Micro-cantilever ESR [4], which enables the ESR detection of micrometer size samples.

Recently we have extended the micro-cantilever ESR measurements up to 1.1 THz, which is the

world record for such mechanical detection of ESR, using the torque method [5].

In connection to micro-cantilever ESR, the development of magnetization detected ESR using

SQUID (Superconducting Quantum Interference Device) magnetometer (SQUID ESR) is also

achieved.

Finally the future perspectives of multi-extreme THz ESR will be discussed.

References:

1. H. Ohta et al., J. Low Temp. Phys. 2013, 170, 511. 2. T. Sakurai et al., Rev. Sci. Inst. 2007, 78, 065107; T. Sakurai, J. Phys.: Conf. Series, 2010, 215, 012184. 3. K. Fujimoto et al., Appl. Mag. Res. 2013, 44, 893; H. Ohta et al., J. Phys. Chem. B 2015, 119, 13755; T. Sakurai et

al., J. Mag. Res., 2015, 259,108. 4. H. Ohta et al., AIP Conf. Proceedings 2006, 850, 1643; E. Ohmichi et al., Rev. Sci. Instrum. 2008, 79, 103903; E.

Ohmichi et al., Rev. Sci. Instrum. 2009, 80, 013904; H. Ohta and E. Ohmichi, Appl. Mag. Res. 2010, 37, 881; E. Ohmichi et al., J. Low Temp. Phys. 2010, 159, 276; Y. Tokuda et al., J. Phys.: Conf. Series 2012, 400, 032103; E. Ohmichi et al., J. Mag. Res. 2013, 227, 9.

5. H. Takahashi, E. Ohmichi, H. Ohta, Appl. Phys. Lett. 2015, 107, 182405. 6. T. Sakurai et al., J. Phys.: Conf. Series 2011, 334, 012058; T. Sakurai et al., J. Mag. Res. 2012, 223, 41; T. Sakurai et

al., J. Magnetics 2013, 18, 168.

PL-01


26

New Approaches in Pulsed EPR for Studying Structure and

Dynamics of Lipid Membranes

S.A. Dzuba

Institute of Chemical Kinetics and Combustion, Novosibirsk, 630090 Russia and

Novosibirsk State University, Novosibirsk, 630090, Russia


There is accumulating evidence for heterogeneous lipid composition of plasma membranes.

Membranes are assumed to contain lipid rafts – fluctuating nanoscale assemblies of lipids,

cholesterol, peptides and proteins, – which are thought to form platforms functioning in membrane

signaling and trafficking. Here, we explore heterogeneities of lipid bilayers using electron spin echo

(ESE) of spin labels. An approach is used utilizing the effects of so-called “instantaneous spectral

diffusion” in electron spin echo (ESE) [1]. These effects are induced by pulse modulation of

magnetic dipole-dipolar interactions between spin labels; which is similar to the effect of pulsed

electron-electron double resonance (DEER or PELDOR). As compared with DEER, ESE is more

suitable for exploring heterogeneities in local concentration.

Using this ESE approach, nanoclusters were found for guest molecules in phospholipid bilayers

where guests were either spin-labeled 5-DOXYL-stearic acid, or palmitoyl-stearoyl-(5-DOXYL)-

sn-glycero-phosphocholine, or 3β-doxyl-5α-cholestane. The local concentration in nanoclusters may

attain values exceeding the mean concentration in the bilayer by an order of magnitude.

The presence of peptide antibiotic alamethicin was found to destroy these local nanoclusters in

bilayeres, with guest molecules becoming distributed uniformly in the membrane. This effect of

homogenization of structure of biological membranes appears even at very small peptide

concentration in membrane – for the 1000/1 peptide/lipid molar ratio. Probably, such

homogenization can provide important antimicrobial mechanism of the alamethicin action.

Recently, an Electron Spin Echo Envelope Modulation (ESEEM) approach was developed for

detection of motion of deuterated molecules near the spin label [2]. This approach may be applied to

study motions in the hydration shell of biological membranes. It is shown that water molecules near

the membrane surface (~ 0.5 nm away) are mobile even at temperatures below 200 K, and that

water molecular motion is influenced noticeable by the membrane lipid composition.

References: 1. M.E. Kardash, S.A. Dzuba, J. Chem. Phys., 2014, 141, 211101. 2. V.N. Syryamina et al. J. Magn. Reson. 2015, 261, 169-174.

Acknowledgements:

This work was supported by the Russian Science Foundation, project # 15-15-00021 and by the Russian

Foundation for Basic Research, project # 15-03-02186.

PL-02


27

Correlation of EPR-measured Tumor Microenvironment Parameters using

Multifunctional Trityl Probe

Valery V. Khramtsov,1 Andrey A. Bobko,

1 Benoit Driesschaert,

1 Ilirian Dhimitruka,

2 Jason Evans,

2

Mikhail M. Dikov2 and Timothy D. Eubank

1

1 West Virginia University, In Vivo Multifunctional Magnetic Resonance center, Robert C. Byrd Health

Sciences Center, Morgantown, WV 26506 2 The Ohio State University, Department of Internal Medicine, Columbus, OH 43210


Recently designed monophosphonated trityl probe, pTAM, allows for in vivo concurrent EPR

assessment of physiologically important chemical parameters including oxygen, pO2, extracellular

acidosis, pHe, and interstitial inorganic phosphate, Pi 1. Here we used pTAM probe and L-band EPR

spectroscopy for in vivo multifunctional assessment of tumor microenvironment (TME) in various

animal models of cancer. The observed slightly lower mean values of pO2 and pHe in TME of

PyMT transgenic mice compared to normal mammary glands support existence of hypoxic and

acidic areas in TME. The most dramatic differences between tumors and normal tissues were

observed for interstitial [Pi], being about 2-3-fold higher in tumors. In mouse tumor xenograft

models the only parameter which allowed for discrimination between non-metastatic PC14 and

highly metastatic PC14HM tumors was extracellular Pi presented in about 2 fold higher

concentrations in TME of highly metastatic tumors. Multifunctional spectral properties of pTAM

probe allows for correlation analysis between three measured parameters. Interstitial [Pi] negatively

correlated with pO2 in normal and tumor tissues supporting association of high [Pi] with changes in

bioenergetics status upon decrease in oxygen supply. A negative correlation was found between pO2

and pHe in normal mammary gland vs. absence of correlation in tumors supporting reliance of

cancer metabolism on glycolysis independent of oxygen concentration (Warburg effect). The

absence of correlation between pHe and Pi in all measured tissues apparently reflect different

mechanisms of protons and phosphate accumulation in TME. In summary, our studies

unambiguously identifies interstitial inorganic phosphate as a new TME marker of tumorigenesis,

tumor progression and aggressiveness.

References:

1. Bobko et al., Angew. Chem. Int. Edit. 2014, 53, 2735-2738.

Acknowledgements:

Supported by NIH grants CA194013, CA192064 and U54GM104942.

PL-03


28

Ultra-wideband pulse EPR spectroscopy

Andrin Doll, Takuya Segawa, Stephan Pribitzer, Frauke Breitgoff,

Yevhen Polyhach, Gunnar Jeschke

Lab. Phys. Chem., ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland


EPR spectra of organic radicals, such as nitroxide spin labels, in the solid state are typically 150-500

MHz wide while spectra of transition and rare earth metal ions usually exceed a bandwidth of 1 GHz. Ultra-

wideband excitation (>500 MHz) is then required for optimizing sensitivity [1] and for detecting Fourier-

transform (FT) EPR spectra with tolerable line shape distortions [2]. Based on a fast arbitrary waveform

generator (AWG) with built-in sequencer we have built a coherent pulse EPR spectrometer that can perform

such experiments at X-band [2] and Q-band [3] frequencies. Alternatively, output from the same AWG can

feed an incoherent pump pulse channel of a commercial spectrometer [1,4]. Pump bandwidths of up to 2.5

GHz [4] and coherent FT-EPR detection with some edge attenuation over 0.8 GHz bandwidth [5] have been

achieved with such instrumentation. This allowed for sensitivity enhancement by polarization transfer from

satellite transitions to the central transition of S = 7/2 Gd(III) ions [4], for a substantial increase of the

modulation depth in Gd(III)-Gd(III) double electron electron resonance (DEER) experiments [6], and for

correlating copper nuclear frequencies of up to 200 MHz to FT-EPR spectra by two-dimensional electron

spin echo envelope modulation (ESEEM) and three-dimensional hyperfine sublevel correlation (HYSCORE)

experiments [5].

Simulation of such experiments requires a computationally efficient and convenient software package

that we have provided by the free open-source Matlab toolbox SPIDYAN [7]. Based on SPIDYAN

simulations and theoretical considerations we discuss features and limitations of frequency-swept pulses [8].

The most important limitation by the resonator bandwidth can be alleviated by a transformation of the

frequency modulation function that ensures offset-independent adiabaticity [1,3]. Depending on the type of

experiment, pulse length may be limited by electron spin relaxation times, or, more strongly, by the strength

of interactions. In the latter case, high pulse power and optimal use of this power are important, as is

discussed for a two-dimensional SIFTER/FT-EPR correlation experiment and for the suppression of artefacts

in five-pulse DEER. On the example of chirp-induced dipolar modulation enhancement (CIDME) we

illustrate how this limitation can be overcome.

References:

1. A. Doll, S. Pribitzer, R. Tschaggelar, G. Jeschke, J. Magn. Reson. 2013, 230, 27-39. 2. A. Doll, G. Jeschke, J. Magn. Reson. 2014, 246, 18-26. 3. A. Doll, Diss. ETH 23332, 2016, DOI: 10.3929/ethz-a-010670425 4. A. Doll, M. Qi, S. Pribitzer, N. Wili, M. Yulikov, A. Godt, G. Jeschke, Phys. Chem. Chem. Phys. 2015, 17, 7334-

7344. 5. T. F. Segawa, A. Doll, S. Pribitzer, G. Jeschke, J. Chem. Phys. 2015, 143, 044201. 6. A. Doll, M. Qi, N. Wili, S. Pribitzer, A. Godt, G. Jeschke, J. Magn. Reson. 2015, 259, 153-162. 7. S. Pribitzer, A. Doll, G. Jeschke, J. Magn. Reson. 2016, 263, 45-54. 8. G. Jeschke, S. Pribitzer, A. Doll, J. Phys. Chem. B 2015, 119, 13570−13582.

Acknowledgements:

Funding from the ETH research Grant ETHIIRA-23 11-2, from the DFG priority programme SPP 1601 (Grants JE

246/5-1, JE 246/5-2) and from the SNSF Grants 20020_157034 is gratefully acknowledged.

PL-04


29

Following the Fate of Free Radicals Using EPR and Fluorescence

Steven Bottle, James Blinco and Liam Walsh

School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology

[email protected]

Nitroxides are highly versatile EPR probes, powerful antioxidants and very efficient scavengers

of free radicals. The six-membered ring TEMPO class has attracted the most interest; however other

systems, including fused aryl nitroxides, can also display important properties. Significantly, when

the nitroxide group is combined with a conjugated fluorophore, excited state quenching and energy

transfer essentially short-circuits the usual fluorescence emission. However, when the nitroxide

captures a free radical to form an alkoxyamine, the natural fluorescent nature of the conjugated

systems returns. Incorporating nitroxides within fluorophores therefore allows the monitoring of

radical reactions by both the level of fluorescence emission generated and the loss of the EPR signal

as the nitroxide is converted to the diamagnetic (and fluorescent) product.1 We have described such

nitroxide-fluorophore systems as profluorescent nitroxides (PFNs) and they represent important

new analytical tools.

A brief overview is presented that describes the synthesis of some novel nitroxides that have

found applications probing the free radical basis of oxidative diseases,2 as sensors for oxidative

damage in materials3 and even for monitoring pollution from ultra-fine particles.

4 Of particular

interest is the use of PFNs to investigate the manner by which nitroxides provide protection to

polymers by retarding oxidative degradation in a process that is known as the “Denisov cycle”. It is

remarkable that almost 40 years after their commercialisation, the exact manner by which nitroxides

extend the application lifetime of polymers (in some cases with reaction stoichiometries of >500

equivalents5) is still the subject of some debate.

6 Using nitroxides, EPR and fluorescence allows us

to shed some new light on this puzzling process.

References: 1. J.B. Blinco, K.E. Fairfull-Smith, B.J. Morrow, S.E. Bottle, Australian Journal of Chemistry (2011), 64(4), 373-389. 2. a) C.L. Rayner, S.E. Bottle, G. Gole, MS. Ward, N.L. Barnett, Neurochemistry International (2015), 92, p1-12. b)

B.J. Morrow, D.J. Keddie, N. Gueven, M.F. Lavin, S.E Bottle, Free Radical Biology & Medicine (2010), 49(1), 67-76. c) Ahn H, Fairfull-Smith K.E., Morrow B.J., Lussini V., Kim B., Bondar M.V., Bottle S.E., Belfield K.D. J. Am. Chem. Soc. (2012), 134, 4721−4730

3. a) K.E. Fairfull-Smith, J.P. Blinco, D.J. Keddie, G.A. George and S.E. Bottle, Macromolecules (2008), 41(5), 1577-1580. b) J.M. Colwell, J.R. Walker, J.P. Blinco, A.S. Micallef, G.A. George, S.E. Bottle, Polym. Deg. Stab., (2010), 95(10), 2101-2109.

4. a) B. Miljevic, M.F. Heringa, A. Keller, S.E. Bottle et al. Environmental Science & Technology (2010), 44(17), 6601-6607. b) Miljevic B, Fairfull-Smith KE, Bottle SE, Ristovski Z, Atmospheric Environment (2010), 44(18), 2224-2230.

5. T. Bolsman, A. Blok, J. Frijns Recl. des Trav. Chim. des Pays-Bas (1978), 97, 310-312. 6. G. Gryn’ova, K.U. Ingold, M.L. Coote, J. Am. Chem. Soc., (2012), 134, 12979−12988.

PL-05

mailto:[email protected]


30

Quantum control of spins in solids and its applications

Jiangfeng Du

National Laboratory for Physics Sciences at the Microscale and Department of Modern Physics, University

of Science and Technology of China, Hefei, 230026, China

The science of quantum control lies at the heart of modern physics. Various applications of

quantum control have emerged and we witness great development in recent years, such as quantum

computation, quantum simulation, and quantum metrology, etc. Spins of electrons and nuclei are

among the most promising physical systems that can realize reliable and robust quantum control.

They have a major advantage since the quantum coherence can be protected very efficiently against

external noise, which represents the main challenge to the large-scale implementation of quantum

control.

My presentation will mainly focus on our recent experimental study of quantum control over

spins in solids. We concern on several respects such as decoherence suppressing with dynamical

decoupling [1,2], precise spin control[3,4], efficient realization of quantum algorithms[5] and

simulation[6], and ultrasensitive sensing with single spins in diamond[7,8].

This work is supported by 973 Program (Grant No. 2013CB921800) and the NNSFC.

References: 1. Jiangfeng Du*, Xing Rong, Nan Zhao, Ya Wang, Jiahui Yang, and R. B. Liu*, Preserving electron spin coherence

in solids by optimal dynamical decoupling, Nature 461, 1265 (2009). 2. Ya Wang, Xing Rong, Pengbo Feng, Wanjie Xu, Bo Chong, Ji-Hu Su, Jiangbin Gong, and Jiangfeng Du*,

Preservation of Bipartite Pseudoentanglement in Solids Using Dynamical Decoupling, Physical Review Letters 106, 040501 (2011).

3. Xing Rong, Jianpei Geng, Zixiang Wang, Qi Zhang, Chenyong Ju, Fazhan Shi, Chang-Kui Duan*, and Jiangfeng Du*, Implementation of dynamically corrected gates on a single electron spin in diamond, Physical Review Letters 112, 050503 (2014)

4. Xing Rong, Jianpei Geng, Fazhan Shi, Ying Liu, Kebiao Xu, Wenchao Ma, Fei Kong, Zhen Jiang, Yang Wu, and Jiangfeng Du*, Experimental fault-tolerant universal quantum gates with solid-state spins under ambient conditions, Nature Communications 6, 8748 (2015)

5. Fei Kong, Chenyong Ju*, Pu Huang, PengfeiWang, Xi Kong, Fazhan Shi, Liang Jiang*, and Jiangfeng Du*, Experimental Realization of High-Efficiency Counterfactual Computation, Physical Review Letters 115, 080501 (2015).

6. Zhaokai Li, Hui Zhou, Chenyong Ju*, Hongwei Chen, Wenqiang Zheng, Dawei Lu, Xing Rong, Changkui Duan, Xinhua Peng*, and Jiangfeng Du*, Experimental Realization of a Compressed Quantum Simulation of a 32-Spin Ising Chain, Physical Review Letters 112, 220501 (2014)

7. Fazhan Shi, Xi Kong, Pengfei Wang, Fei Kong, Nan Zhao, Ren-Bao Liu, Jiangfeng Du*, Sensing and atomic-scale structure analysis of single nuclear spin clusters in diamond, Nature Physics 10, 21 (2014).

8. Fazhan Shi, Qi Zhang, Pengfei Wang, Hongbin Sun, Jiarong Wang, Xing Rong, Ming Chen, Chenyong Ju, Friedemann Reinhard, Hongwei Chen, Jörg Wrachtrup, Junfeng Wang, and Jiangfeng Du*, Single-protein Spin Resonance Spectroscopy under Ambient Conditions, Science 347, 1135 (2015).

PL-06

"Asia-Pacific EPR/ESR Symposium-2016" August, 28 – September, 02, 2016, Irkutsk, Russia

31

ATPase mechanism of ABC exporters and RNA helicases explored by time

resolved high field hyperfine spectroscopy

A. Collauto,1 S. Mishra,

2 M. Bye,

1 H. S. Mchaourab,

2 D. Goldfarb

1

1Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel

2Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States

Several classes of enzymes transduce the energy from ATP hydrolysis, taking place in the

presence of the metal cofactor Mg2+

, into molecular motion. Mechanistic insights into this process,

which is essential for their specific activities, can be obtained by elucidating the pathway through

which ATP hydrolysis is coupled with conformational rearrangements. In such systems the position

along the reaction coordinate can be assessed by substituting the essential diamagnetic metal

cofactor Mg2+

with the paramagnetic Mn(II) (S = 5/2, I = 5/2) and probing the hyperfine interaction

between the unpaired electron spin of the Mn(II) and the nuclear spin of the 31

P nuclei (I = 1/2) of

the nucleoside phosphate coordinated to the metal ion. This hyperfine interaction, which was found

to report on the hydrolysis state of the nucleoside phosphate [1], can be measured with electron

paramagnetic resonance (EPR) techniques, specifically electron-nuclear double resonance

spectroscopy (ENDOR) or electron-electron double resonance (ELDOR)-detected nuclear magnetic

resonance spectroscopy (EDNMR).

Using a high field/high frequency spectrometer (94.9 GHz, ≈ 3.5 T), the proposed methodology

is applied to follow the ATPase kinetics of (i) the E. Coli DEAD-box helicase DbpA [1] and (ii) the

bacterial ATP-binding cassette (ABC) exporters MsbA and BmrCD [2]. We show that in 31

P-

ENDOR the ATP hydrolysis state is mainly contained in the spectral lineshape, whereas in 31

P-

EDNMR this information is mainly associated with the signal intensity. A direct proportionality is

found between this latter parameter and the fraction of ATP in ATP:ADP mixtures; this allows to

extract quantitative information about the reaction kinetics from the spectroscopic measurements.

References: 1. I. Kaminker et al., J. Am. Chem. Soc. 2011, 133, 15514. 2. S. Mishra et al., eLife 2014, 3:e02740.

PL-07


32

What are the concentration sensitivity and time resolution limits

for pulsed EPR?

G.M. Smith, C. Motion, J. McKay, R.I. Hunter, D.R .Bolton, H. El Mkami

School of Physics and Astronomy, University of St Andrews, Scotland


Concentration sensitivity is perhaps the most important parameter for the majority of cw and

pulse EPR experiments, and for many years it had been thought that only incremental

improvements were achievable. At X-band, a wide variety of cavities had been investigated and

optimized for different applications, and scaling laws had suggested, that at least in terms of

concentration sensitivity, there was little advantage in moving to higher frequencies. However, in

the last few years these accepted tenets have been turned on their head. Rapid scan techniques have

shown that significant gains in cw sensitivity are possible, and the move to higher frequencies at

high power levels with oversized samples has led to major increases in pulsed EPR sensitivity.

Today, many leading labs are almost abandoning their old X-band pulsed systems and moving to

high power pulsed Q-band systems because of the enormous gains in productivity possible. In

parallel the availability of fast Arbitrary Waveform Generators is opening up new ways of

improving sensitivity for many standard experiments, and at high frequencies component and

systems technology is rapidly improving, leading to further potential gains.

In this paper, I will provide a variety of proof of principle experiments that suggest that

concentration sensitivity improvements by factors of 1000 are realistic for high power W-band

systems, relative to current X-band pulsed measurements. This level of instrumental gain would

allow PELDOR measurements on protein systems at physiological concentrations (e.g. in cell). It

would allow a much wider variety of biological systems to be investigated whose concentration is

currently limited by aggregation effects or by the amount of sample available. In many cases it

would make multi-dimensional experiments viable because of the huge reduction in averaging time.

It also would allow direct EPR measurements during high power pulses (i.e. with zero deadtime).

Such measurements require extremely high isolation between the transmitter and receiver, and

sensitivity now depends on signal to clutter rather than signal to noise. However, I will show W-

band experiments using this technique are realistic and permit very short (sub 10ns) T1 and T2

relaxation times to be directly measured at experimentally useful concentration levels, with

relevance for DNP, dynamics and time resolved measurements. I will also show that the use of

shaped pulses has potential to further improve performance and make FID detection more generally

applicable to pulsed EPR.

PL-08


33

Fascinating phase diagrams of doped rare-earth manganites: insights from

electron magnetic resonance and magnetization studies

S.V. Bhat, K.S. Bhagyashree

Department of Physics, Indian Institute of Science, Bengaluru-560012, India

E-mail: [email protected], [email protected]

The studies of doped rare-earth manganites [1] over the last couple of decades constitute

arguably the most investigated area in condensed matter physics after the advent of high-

temperature superconductors. These manganites have the general formula TxD1-xMnO3 where T is a

trivalent rare earth ion such as La3+

, Nd3+

, Pr3+

…etc. or Bi3+

and D is a divalent alkaline earth ion

such as Ca2+

, Sr2+

, …etc. The parent compounds TMnO3 and DMnO3 have antiferromangnetic

ground states. However, partial substitution of T3+

ions with D2+

ions leads to a plethora of phases

marked by fragile phase boundaries for 0 < x < 1. The doping results in mixed-valent compounds

with Mn3+

and Mn4+

ions, the ratio of which greatly controls the properties. An intimate coupling

between different parameters such as spin, charge and orbital orientation gives rise to a number of

interesting phenomena like colossal magnetoresistance (CMR), charge ordering (CO), metal

insulator transitions, magnetic transitions and phase co-existence. It may be pertinent to note here

that scientists from countries like China, India, Japan and Russia in the Asia-Pacific Region have

been significant contributors to this field.

Since the spin interactions are at the root of many interesting phenomena in manganites, it is

not surprising that EPR/EMR and magnetization studies, along with structural investigations, have

been the techniques of choice for the study of these materials. Our effort has been mainly in the

study of the CO phenomenon and its disappearance on reduction of the size of the particles to

nanoscale [2]. In an early work [3] it was shown that EPR provides tell-tale signatures of the CO

state and can provide clues to understanding the physics behind the phenomenon. This was followed

by the investigations of the effect of ‘two-electron doping’ in Ce based manganites, disappearance

of charge order and emergence of ferromagnetism(FM) in nanowires and nanoparticles, so called

‘electron-hole asymmetry’ in bulk manganites and its disappearance in nanomanganites [4].

In this presentation, the highlights of these previous works will be briefly discussed. Then we

shall take up our most recent and somewhat exciting results for detailed analysis. This pertains to

the EPR and magnetization studies of bulk and nanoparticles of La1-xSrxMnO3: x = 0.15, (LSMO15)

and x = 0.125, (LSMO125). It is observed that bulk LSMO15 exhibits a rarely observed

temperature dependent switch of the sign of the magnetocrystalline anisotropy. This is understood

as a consequence of the Jahn-Teller (JT) transition occurring within the ferromagnetic phase. In

bulk LSMO125, JT transition occurs at a higher temperature than the FM transition and

consequently there is no switch of the sign of magnetocrystalline anisotropy. However,

nanoparticles of LSMO125 exhibit this switch! This is quite unexpected since it would imply a

change in the order of the FM and JT transitions on size reduction. While it is necessary to confirm

this result by other studies, this, most likely the first such observation, has important implications

for theories of manganite physics.

References 1. Y. Tokura, Reports on Progress in Physics, 2006, 69, 797 2. S. S. Rao, S. Tripathy, D. Pandey, S. V. Bhat, Phys. Rev, B, 2006, 74, 144416 3. J. P. Joshi et al., Phys. Rev. B, 2002, 65, 024410 4. K. S. Bhagyashree and S. V. Bhat, J. Appl. Phys., 2015, 117, 17D514

Acknowledgements: SVB thanks the Indian National Science Academy, Delhi for support.

PL-09


34

Molecular Lanthanide Spin Qubits

Stephen Hill,1,2

Dorsa Komijani,1,2

Muhandis Shiddiq,1,2

Yan Duan,3 Alejandro Gaita-Ariño,

3

Alberto Ghirri,4 Marco Affronte,

4 Eugenio Coronado

3

1Department of Physics, Florida State University, Tallahassee, FL 32306, USA

2National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA

3Instituto de Ciencia Molecular, Universidad de Valencia, 46980 Paterna, Spain

4CNR and Università di Modena & Reggio Emilia, I-41125 Modena, Italy


Interdisciplinary research into the utility of magnetic molecules for quantum computing

applications represents one of the frontiers of materials science. This lecture will describe recent

results of continuous-wave (cw) and pulsed EPR studies on related families of lanthanide

containing molecules that have attracted tremendous interest as potential hybrid electron-nuclear

spin qubits. A molecular approach is attractive because it enables systematic control of the quantum

states of the lanthanide (the qubit) via molecular geometry, and allows functionalization of the

molecule in order to engineer interactions between qubits.

The first example involves a HoIII

(4f 10

) ion encapsulated within a (W5O18)2 cage. The Ho ion

experiences a significant magnetic anisotropy due to crystal-field splitting of the spin-orbit coupled

total angular momentum (J = L + S = 8) ground state, resulting in a pair of low-lying mJ = ±4

singlets that are further split by a strong hyperfine interaction with the I = 7/2 nuclear spin [1]. A

small departure from a square antiprismatic (D4d symmetry) coordination geometry results in a

Zeeman diagram (with B parallel to the molecular symmetry axis) with multiple avoided crossings

between the 16 [(2I + 1) 2] lowest-lying electron-nuclear sub-levels. Right at these avoided

crossings, the EPR transition frequencies are insensitive to dipolar field fluctuations associated with

the surrounding electron/nuclear spin bath, which represent the main source of decoherence. These

so-called ‘atomic clock transitions’ (named after the principle which gives atomic clocks their

exceptional phase stability) give rise to long coherence (T2) times [2]. Formally forbidden mI = ±1

hybrid electron/nuclear clock transitions are also observed upon application of a transverse field.

The 2nd

example involves bis-phthalocyanine radical coupled to a TbIII

ion, revealing a highly

anisotropic signal that is attributed to the radical, suggesting a significant coupling to the lanthanide

spin [3]; the radical EPR spectrum would be expected to be essentially isotropic otherwise. This

work is important given the recent demonstration that radical bearing ligands provide a means of

addressing lanthanide qubits integrated into single-molecule devices.

References:

1. S. Ghosh, S. Datta, L. Friend, S. Cardona-Serra, A. Gaita-Ariño, E. Coronado, S. Hill, Dalton Trans., 2012, 41, 13697-13704.

2. M. Shiddiq, D. Komijani, Y. Duan, A. Gaita-Ariño, E. Coronado, S. Hill, Nature, 2016, 531, 348-351. 3. D. Komijani, A. Ghirri, M. Affronte, M. Ruben, S. Hill, in preparation.

Acknowledgements:

This work was supported by the US National Science Foundation (grant number DMR-1309463) and AFOSR

(AOARD contract # 134031 FA2386-13-1-4029). The NHMFL is supported by the NSF (DMR-1157490) and the

State of Florida.

PL-10

INVITEDTALKS


35

ESR sensitivity – current capabilities and future prospects and applications

Aharon Blank

Schulich Faculty of Chemistry, Technion – Israel Institute of Technology, Haifa, 32000, Israel


One of the most significant hurdles that limit the applicability of ESR technology towards new

biological and materials science applications is its low sensitivity. ESR sensitivity can be related to

two, somewhat complementary terms: Absolute spin sensitivity and concentration sensitivity. The

former relates to the minimal number of spins that can be measured by the system for 1 s of

acquisition time (denoted in units of spins/√Hz), while the latter to the minimal measured spin

concentration (denoted in units of molar/√Hz). Different applications would dictate different

sensitivity requirements and thus steer towards the preferable spectrometer and probehead

configuration. For example, if there are sever limitations on the size of the sample available for

measurements then usually the goal would be to measure it with systems having high spin

sensitivity, while if sample is not limited, but one cannot increase its concentration (for various

reasons: aggregation, mincing biological conditions or cells' measurements), a system with high

concentration sensitivity would be the preferable alternative.

This talk will focus on the theoretical and practical aspects of current and future methods for

achieving high spin sensitivity. We will first provide a short review of available spin detection

methods and try to compare them all using a unified standard scale. We will then focus on

induction detection and provide more detailed expression for the spin sensitivity both from a

classical and a quantum view point, showing for the first time the equivalence of these two

approaches. Theoretical calculations will be followed by some examples of recent experimental

results detecting very few electron spins. Finally, we will draw some conclusions about the

prospects and potential applications of high spin sensitivity for the field of ESR.

Acknowledgements:

This work was partially supported by grant #310/13 from the Israel Science Foundation (ISF), and grant #FA9550-13-1-

0207 from the Air Force Office of Scientific Research (AFOSR).

IN-01


36

ELDOR-detected NMR: a powerful EPR technique for hyperfine and

polarization transfer studies

Anton Savitsky

Max-Planck-Institut für Chemische Energiekonversion

Stiftstr. 34-36, Mülheim and der Ruhr


ELectron-electron DOuble Resonance (ELDOR)-detected NMR (EDNMR) is growing in

popularity as a means to characterize the hyperfine structure of complex chemical systems. First

developed in the Schweiger laboratory,1 it uses selective microwave pulses which simultaneously

pump EPR and NMR transitions of the spin manifold, so called spin-forbidden transitions, where

both the electron and nuclear spins change their projection direction (mS = ±1, mI = ±1, ±2). As

compared to conventional ENDOR techniques it has a much higher sensitivity and does not exhibit

nucleus-dependent or pulse-dependent spectral artifacts and does not require additional radio-

frequency hardware. Historically, the wide spread adoption of EDNMR has been hampered by what

is termed the central blind spot. Spin-forbidden transitions that are sufficiently close in absolute

frequency to the allowed EPR transition are masked due to the simultaneous pumping of this

allowed transition, i.e. transitions within 5-10 MHz. This problem can, however, be solved by

performing experiments at high magnetic fields and, thus, higher nuclear Larmor frequencies.

In this presentation the EDNMR technique is introduced. It general applicability for hyperfine

studies is discussed. Several examples are given which include the experimental results on nitroxide

radicals2,3

and transition-metal containing systems4,5

. Advantages and disadvantages of the method

as compared to conventional ENDOR and ESEEM techniques are pointed out. Additionally,

selected examples of EDNMR application to electron-nuclear polarization transfer studies are

presented using molecular systems containing Mn(II) and Gd(III) tags.

References:

1. P. Schosseler, T. Wacker, A. Schweiger, Chem. Phys. Lett. 1994, 224, 319-324. 2. Nalepa A., Möbius K., Lubitz W., Savitsky A., J. Magn. Reson. 2014, 242: 203-213 3. Cox N., Nalepa A., Pandelia M.-E., Lubitz W., Savitsky A., 2015, In: Peter ZQ, and Kurt W (eds) Methods in

Enzymology, Vol. Volume 563, pp. 211-249, Academic Press 4. Rapatskiy L., Ames W.M., Perez-Navarro M., Savitsky A., Griese J.J., Weyhermueller T., Shafaat H.S., Hogbom M.,

Neese F., Pantazis D.A., Cox N., J. Phys. Chem. B 2015, 119, 13904-13921 5. Cox N., Lubitz W., Savitsky A., Mol. Phys. 2013, 111: 2788-2808

IN-02


37

Discovery and Identification of Dinitrosyl Iron Complexes with Thiol-containing

Ligands in Biological Objects by the EPR Method

Anatoly F. Vanin

Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia

It is has been demonstrated how the use of only one physico-chemical approach, viz., the

electron paramagnetic resonance (EPR) method, allowed detection and identification of dinitrosyl

iron complexes (DNIC) with thiol-containing ligands in animal tissues and bacterial cells. These

complexes occur in biological objects in the paramagnetic (EPR-active) mononuclear and

diamagnetic (EPR-silent) binuclear forms and control the activity of nitrogen monoxide (NO), one

of the most universal regulators of metabolic processes occurring in the organism.

The mononuclear form of DNIC (M-DNIC) was the first to be detected in our laboratory, first

in yeast cells (1964) and, some time later, in animal tissues (1967) by the characteristic EPR signal

with the following values of the g-factor: g =2.04, g = 2.014, gaver.= 2.03 (the so-called 2.03

signal). The nature of the centers responsible for this signal was identified after the discovery that

the EPR signal recorded in frozen aqueous solutions of М-DNIC with cysteine and glutathione is

identical to the 2.03 signal. The analysis of the electronic and spatial structures of M-DNIC based

on their EPR characteristics shed additional light on the mechanism of formation of DNIC with

thiol-containing ligands and the functional role of these complexes in human in animal cells as

donors of NO and its ionized form, viz., nitrosonium ions (NO+).

With the decrease in the concentration of thiol-containing compounds in the test system, the

chemical equilibrium between М- and B-DNIC is shifted towards B-DNIC. Quite probably, in

animal favours the formation of DNIC with thiol-containing ligands, predominantly of their B-form.

Their presence in body tissues can be established by treatment of the latter with dithiocarbamate

derivatives, e.g., diethyldithiocarbamate (DETC) and N-methyl-D-glucamine dithiocarbamate

(MGD). These compounds accept one iron-mononitrosyl group from iron-dinitrosyl [Fe(NO)2]

fragments of B-DNIC and thus initiate the formation of EPR-active hydrophobic and hydrophilic

mononitrosyl iron complexes (MNIC) with DETC or MGD, respectively.

It was found also that B-DNIC with thiol-containing ligands are formed in animal tissues in

significant amounts comparable to those of NO. This and the high biological activity of B-DNIC

and М-DNIC commensurate to that of NO provide conclusive evidence that both types of DNIC

represent a "working" form of endogenous NO.

IN-03


38

Spin dynamics and Magnetic Field Effect in Flavin containing photochemical

systems studied by static and pulsed magnetic field

Kiminori Maeda

Department of Chemistry, Graduate School of Science and Engineering, Saitama University,

Saitama 338-8570, Japan.


In the last decade, magnetoreception of Flavin containing systems are actively studied from the

interests on the blue light receptor protein such as Cryptchrome or Photolyase[1]. Recently, the

group containing the author has presented the consistent Magnetic Field Effect (MFE) on the photo-

induced chemical reaction of Cryptochromes and Photolyases by the transient absorption[2], cavity

enhanced spectroscopy and the cavity ringdown spectroscopy[1]. However, it was still difficult to

detect the magnetic field effect in the field as weak as the earth magnetic field.

The cavity based detection improved the sensitivity for the detection of the very small

absorption by the intermediate radicals. However, there are still the problems as follows.

1). In order to study the optimal condition for the molecular magnetoreception, the precise

analysis of the MFE spectra is very important. Therefore, the improvement of signal to noise of

MARY spectra is still the issue for the purpose.

2). The radical pair lifetime is very crucial factor for the magnetoreception. However, the time

resolution of the cavity based spectroscopy often does not have enough good time resolution

3) The typical reaction of Flavin containing supermolecular systems, which can be regarded as

the model of the blue light receptor protein, makes the system with the transformation from radical

pair 1 to radical pair 2. However, it is very hard to discriminate the magnetosensitive RP1 from

RP2.

In the present talk, the author presents the following efforts to improve the MFE measurement

targeting the Flavin containing radical pair systems.

The author has noticed that the fluctuation of the pump laser pulse is the most serious source of

scattering the data in MARY spectra. On this occasion, the author has started to use a diode pumped

YAG laser, which is about ten times as stable as a flash lamp pumped laser.

For the problem (2) and (3), a nano-second magnetic field switching technique has been

applied to determine the life time of the primary radical pair.

Using the improved setup, we have studied the details of the spin dynamics of the radical pair

produced by the intramolecular electron transfer reaction of Flavin Adenine dinucleotide (FAD)[3].

The improvement of the new set up gave us the chance to do the detailed analysis of B1/2 values

depending on delay time after the laser flash and quencher concentration.

References:

1. Emrys W. Evans, Charlotte A. Dodson, Kiminori Maeda, Till Biskup, C. J. Wedge, and C. R. Timmel, Interface Focus, 3, 20130037 (2013).

2. Kiminori Maeda, Alexander J Robinson, Kevin B Henbest, Hannah J Hogben, Till Biskup, Margaret Ahmad, Erik Schleicher, Stefan Weber, Christiane R. Timmel, and P. J. Hore Proc. Nat. Acad. Sci. USA, 109, 4774-4779 (2012).

3. Masaaki Murakami, Kiminori Maeda, Tatsuo Arai, J. Phys. Chem. A 109, 5793-5800(2005).

Acknowledgements:

This work is conducted in collaboration with Prof. Jonathan Woodward (University of Tokyo).

IN-04


39

Development of a CW-EPR-based oxygen-mapping technique using a pair of

isotopic nitroxyl radicals

H. Hirata,1 H. Kubota,

1 H. Yasui,

2 S. Matsumoto,

1 O. Inanami,

3 I.A. Kirilyuk

4 and V.V. Khramtsov

5

1Hokkaido University, Division of Bioengineering and Bioinformatics, Sapporo, Hokkaido 060-0814, Japan

2Hokkaido University, Central Institute of Isotope Science, Sapporo, Hokkaido 060-0815, Japan

3Hokkaido University, Graduate School of Veterinary Medicine, Laboratory of Radiation Biology, Sapporo,

Hokkaido 060-0818, Japan 4N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Novosibirsk, 630090, Russia

5West Virginia University, Department of Biochemistry, Morgantown, WV 26506, USA


A feasibility study of CW-EPR-based visualization of the partial pressure of oxygen (pO2) and

the concentrations of nitroxyl radicals is reported. Since the concentration of a spin probe affects its

EPR linewidth (or the relaxation time T2), measurements of pO2 have traditionally required

simultaneous estimation of the probe concentration. Methods for measuring pO2 using

monohydrogenated CTPO (mHCTPO) were developed in the 1990s to overcome this dependence

on the concentration of the probe [1–3]. We revisited this problem to visualize pO2 and the

concentrations of spin probes in a three-dimensional subject. To simultaneously measure unknown

parameters (pO2 and the concentrations of the probes), we used a pair of isotopic nitroxyl radicals,

such as 14

N- and 15

N-labeled dicarboxy-PROXYLs (14

N-DCP and 15

N-DCP) as oxygen-sensitive

spin probes [4]. First, we established simultaneous equations to express the effects of the self-

broadening of 14

N- and 15

N-DCPs, cross-broadening between 14

N- and 15

N-DCPs, and oxygen-

broadening on the linewidths of the probes. To estimate the linewidths of the probes, we used a CW-

EPR-based single-point imaging (SPI) modality [5]. Linewidth maps could be obtained from T2*

maps measured from a mixture of 14

N- and 15

N-DCPs. The concentrations of the probes and pO2

could then be calculated simultaneously by solving the simultaneous equations. This approach

might be useful for oxygen-mapping in biological tissues.

References: 1. H. J. Halpern et al., J. Magn. Reson., 1990, 90, 40–51. 2. H. J. Halpern et al., J. Magn. Reson., 1993, A103, 13–32. 3. H. J. Halpern et al., Proc. Natl. Acad. Sci. USA, 1994, 91, 13047–13051. 4. D. Komarov et al., Magn. Reson. Med., 2016, 76, 350–358. 5. K. Matsumoto et al., Magn. Reson. Med., 2003, 50, 865–874.

Acknowledgements:

This work was supported by JSPS KAKENHI Grant Number 26249057.

IN-05


40

Distance Measurements in Nucleic Acids using Advanced SDSL

with Nitroxyl and Trityl Radicals

Elena Bagryanskaya,1,2

Olesya Krumkacheva,2 Matvei Fedin,

2 Andrei Kuzhelev,

2 Victor Tormyshev,

1

Igor Kirilyuk,1 Elena Babaylova,

4 Galina Karpova,

4 Georgy Shevelev,

4 Dmitry Pyshny

4

1N.N.Vorozhtsov Novosibirsk Institute of Organic Chemistry, Novosibirsk, Russia

2International Tomography Center SB RAS, Novosibirsk, Russia

3Novosibirsk State University Novosibirsk, Russia

4Institute of Chemical Biology and Experimental Medicine, Novosibirsk, Russia

Email: [email protected]

During the last years, tetrathiatriarylmethyl (TAM) radicals have been widely used as spin

probes for oxymetry in electron paramagnetic resonance (EPR) spectroscopy and EPR tomography.

Recently, it was proposed to use TAMs as spin labels for studies on the structure of proteins and

nucleic acids using SDSL and pulsed dipolar EPR spectroscopy [1]. In this talk the peculiarities of

applications of TAMs as spin labels including the distance measurement using TAM spin labels,

electron spin relaxation time, room temperature measurements, and advantages of orthogonal spin

labeling will be presented [2-8].

Recently, we developed promising approach to SDSL of RNAs, which is based on the

complementary-addressed reaction between target RNA residue and a derivative of

oligodeoxyribonucleotide [9]. Contrary to other methods, novel approach is generally applicable to

RNAs of arbitrary size. In this work we apply this approach to SDSL of Hepatitis C Virus (HCV)

RNA Internal Ribosome Entry Site (IRES) consisting of up to 350 nucleotides and having a

complicated spatial structure, and thereby for the first time clearly demonstrate the SDSL of long

structured RNA [10]. Nitroxide spin labels were attached at two definite nucleotide positions of

HCV IRES domain II, as was confirmed by room-temperature continuous wave EPR. Furthermore,

double spin labeling of HCV RNA IRES allowed application of pulsed DEER and obtaining

reasonable spin-spin distance distribution, which agrees well with the results of MD calculations.

Thus, novel complementary-addressed SDSL approach in conjunction with EPR and MD allows

structural studies of long natural RNAs with nanometer resolution and can be applied to systems of

biological and biomedical significance.

mRNAs are involved in complicated supramolecular complexes with human 40S and 80S

ribosomes responsible for the protein synthesis. In our work [11] a derivative of nonaribonucleotide

pUUCGUAAAA with nitroxide spin labels attached to the 5’-phosphate and to the C8 atom of the

adenosine in 6th

position (mRNA analogue) was used for studying such complexes using DEER

spectroscopy. The results of this study are the first demonstration of DEER application for

measurements of intramolecular distances in multicomponent supramolecular complexes involving

intricate cellular machineries and for evaluating dynamic properties of ligands bound to these

machineries.

References: 1. G.W.Reginsson, et al. Chem. A Europ. Journ., 2012, 18, 13580–13584. 2. G. Y. Shevelev, et. al, J. Am. Chem. Soc., 2014, 136 (28), 9874-9877. 3. G. Y. Shevelev, et al. J. Phys. Chem. B, 2015, 119 (43), 13641-13648. 4. A. Kuzhelev, et al. J. Phys. Chem. B 2015, 119 (43), 13630–13640. 5. A. Kuzhelev, et al.. J. Phys. Chem. Lett. 2016, 7 (13), 2544–2548. 6. A. Kuzhelev, et al. J. Magn. Reson. 2016, 266, 1-7 7. A. Lomzov, J. Phys. Chem. B, 2016, 120 (23), 5125-5133. 8. M. Fedin et al. PCCP 2016 submitted. 9. E.Babaylova et al, Org. Biomol. Chem., 2014, 12(19), 3129-3136. 10. E. Babaylova et al , NAR, 2016, doi: 10.1093/nar/gkw516. 11. A. Malygin et al. Biophysical Journal, 2015, 109(12), 2637-2643..

Acknowlegement. This work has been supported by the Russian Science Foundation (grant No. 14-14-00922).

IN-06


41

Effect of dehydrated trehalose matrix on the kinetics of forward electron

transfer reactions in Photosystem I

Alexey Yu. Semenov,1,2

Ivan V. Shelaev,2 Michael Gorka,

3 Anton Savitsky,

4 Vasily Kurashov,

3

Mahir D. Mamedov,1 Fedor E. Gostev,

2 Klaus Möbius,

4 Victor A. Nadtochenko,

2 John Golbeck

3

1A.N. Belozersky Institute of Physical–Chemical Biology, Moscow State University, Moscow, Leninskie

Gory, Moscow 119992, Russia; 2N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia;

3Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park,

PA 16802, USA; 4Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, D-45470 Mülheim (Ruhr), Germany


Effect of dehydration in trehalose glassy matrix on the kinetics of forward electron transfer has

been studied in cyanobacterial Photosystem I (PS I) complexes by flash-induced optical and high-

field time-resolved EPR spectroscopies in the 100 fs –1 ms time domain.

The kinetics of the flash-induced absorption changes in subnanosecond time scale due to the

primary and secondary charge separation steps were monitored by pump–probe laser spectroscopy

with 20-fs low-energy pump pulses centered at 720 nm. The kinetics in ns – ms time domain were

measured by high-field time-resolved EPR spectroscopy and optical spectroscopy at 480 nm.

It was shown that the kinetics of the primary electron transfer reactions due to formation of the

primary P700+A0

- and the secondary P700

+A1

- ion-radical pairs in PS I was not affected by

dehydration in trehalose matrix. However, further forward electron transfer from the phylloquinone

molecules in the A1A- and A1B

- sites to the iron-sulfur cluster FX was decelerated from ~200 ns and

~20 ns in solution to ~15 μs and 60 ns in PS I, respectively. The slowdown of the A1A- FX and

A1B- FX electron transfer in PS I embedded into dry trehalose matrix were similar to those

previously observed at glass transition temperature (~180°K). The significantly different extent of

retardation of the A1A- FX and A1B

- FX electron transfer can be explained by the difference of

activation energies of these reactions. These data indicate that the forward electron transfer beyond

A1- is impaired by restriction of protein dynamics in the dry trehalose glass.

Acknowledgements:

This work was supported by the Russian Science Foundation (Grant 14-14-00789) and by the Russian Foundation

for Basic Research (Grant 15-04-04252).

IN-07



42

Recent development in spin chemistry of photo-generated radical pairs confined

in surfactant-based soft nanomaterials

Tomoaki Miura,1 Kiminori Maeda,

2 Hisao Murai

3 and Tadaaki Ikoma

1,4

1Department of Chemistry, Niigata University. 8050 Ikarashi-2-no-cho, Nishi-ku, Niigata 950-2181, Japan 2Department of Chemistry, Graduate School of Science and Engineering, Saitama University, 255 Shimo-

okubo, Sakura-ku, Saitama338-8570, Japan 3Department of Chemistry, Shizuoka University, 836 Oya, Suruga-ku, Shizuoka 422-8017, Japan

4Center for Instrumental Analysis, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan


Molecular assemblies constructed by amphiphilic molecules in aqueous solutions, such as

micelles and vesicles, are one of the most classical examples of supramolecular nano-cages, which

function as reaction media for confined guest molecules. Photo-generated radical pairs in such

media has been extensively studied since 1970s especially in the field of spin science.[1] A number

of studies with time-resolved EPR and optically-detected magnetic field effect (MFE) have

indicated efficient generation of long-lived (~ 1 s) radical pairs due to the confinement effect.

However, those radical pairs frequently exhibit effective recombination and/or escape, which is

problematic for applications as artificial photosynthesis. Since these unwanted reactions are caused

by diffusion of the guest molecules, the research trend in the field of photochemistry shifted to

fixed-distance covalent donor (D) – acceptor (A) systems.[2]

We have been exploring possibility of constructing D–A systems that exhibit long

recombination lifetimes with small escape yields utilizing the surfactant-based molecular

assemblies. For this purpose, molecular arrangement has been finely tuned taking account of

hydrophobicity/hydrophilicity of the D and A molecules. In the talk, recent achievement regarding

the following two D–A systems will be presented.

D-Chromophore-A triad constructed at a micellar interface, which exhibits sequential electron

transfer and long-distance radical pair generation (> 1 nm).[3]

A long-lived radical pair with negligible escape yield created at an interface of nonionic vesicle

(niosome), which exhibits gigantic MFE over 100%.

Electron transfer kinetics and spin dynamics of radical pairs in those systems have been studied

by time-resolved measurement of MFE, which can be regarded as microwave-free magnetic

spectroscopy. Detailed analysis of the spin dynamics with the aid of theoretical calculations

demonstrates the importance of controlling diffusion dynamics of the radical species confined in the

inhomogeneous cage.

References:

1. N. J. Turro, B. Kraeutler, J. Am. Chem. Soc. 1978, 100, 7432-7434. 2. D. Gust, T. A. Moore, A. L. Moore, Acc. Chem. Res. 1993, 26, 198-205. 3. T. Miura, K. Maeda, H. Murai, T. Ikoma, J. Phys. Chem. Lett. 2015, 6, 267-271.

Acknowledgements:

This work was financially supported by Grant-in-Aid for Young Scientists (B) No. 25810009 and Grant-in-Aid

for Scientific Research (C) No. 15K05384.

IN-08


43

Sterically shielded nitroxides: advanced spin labels with high

stability to reduction

Sergey A. Dobrynin, Natalia M. Kuprikova, Denis A. Morozov,

Yuliya F. Polienko, Irina F. Zhurko, and Igor A. Kirilyuk

1N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Acad. Lavrentyeva Ave. 9,

Novosibirsk, 630090, Russia 2 Novosibirsk State University, Pirogova Str. 2, 630090, Novosibirsk, 630090, Russia


Nitroxides applications in biophysics, structural biology and biomedical research for many

years remain one of the exciting and rapidly developing areas of science. However their use in

biological samples is often complicated due to rapid reduction of nitroxide group with enzymatic

systems and low-molecular biogenic antioxidants. Bulky alkyl substituents adjacent to nitroxide

group may strongly increase nitroxide stability to reduction.[1,2,3] It has been shown recently that

some of the sterically shielded nitroxides may compete with trityl radicals in their stability inside

living cells or in cell extract.[4] This finding opens new prospects for investigation of intracellular

processes using EPR and spin labeling technique.

Various methods of synthesis of sterically shielded nitroxides are described and compared,

including original procedures based on 1,3-dipolar cycloaddition reactions and organometallic

compounds addition to nitrones. A number of new sterically shielded nitroxides have been prepared.

Redox properties and spectral parameters of these radicals are discussed. A set of new spin labels

with high stability to reduction have been prepared.

References:

1. Marx, L.; et al., A. J. Chem. Soc., Perkin Trans. 1, 2000, 1181–1182. 2. Kirilyuk, I. A.; et al. Org. Biomol. Chem. 2004, 2, 1025-1030. 3. Kirilyuk, I. A.; et al. J. Org. Chem., 2015, 80(18), 9118-9125. 4. Jagtap, A. P. et al. Free Radical Res., 2015, 49(1), 78-85.

Acknowledgements:

The work was supported by Russian Science Foundation (No. 14-14-00922).

IN-09


44

EPR Studies on Mechanism of Copper Catalyzed Aerobic Reaction

Yong Li, Min Jiang, Haijun Yang

Department of Chemistry, Tsinghua University, Beijing, 100084, China


Copper compounds are useful transition metal catalysts and are widely used for organocatalytic

synthesis. As an important synthetic method, copper catalyzed aerobic reaction attracts attention

from many organic chemists. On the other hand, there are many disputes about the confirmed

mechanism of copper catalyzed aerobic reaction. A point of view is that in the presence of oxygen,

copper is first oxidated to Cu(III), and Cu(III) as the intermediate plays a important role in

catalyzed reactions. However, it is not clear how oxygen interacts with copper, and there is not any

direct evidence to explain the interaction. As an oxidant, oxygen is easily produces superoxide

radical O2-·, and there are three different valences of copper, Cu(I), Cu(II), and Cu(III) in copper

catalysts. Superoxide radical O2-·and Cu(II) are easily detected using the EPR technique. Therefore,

the EPR technique is a useful method to study the mechanism of copper catalyzed aerobic reaction.

In the present studies, DMSO, KOH and O2 system was selected as an oxidized system, and some

interesting changes in EPR spectra were observed for the oxidized system without and with CuI.

These results will be helpful to explore the mechanism of copper catalyzed aerobic reaction, and to

develope new aerobic reactions.

Figure 1. EPR spectra of the reactions DMSO and KOH and DMSO,KOH and CuI

References:

1. Lauren M. Huffman and Shannon S. Stahl, J. Am. Chem. Soc., 2008, 130, 9196. 2. Amanda E. King, Lauren M. Huffman, Alicia Casitas, Miquel Costas, Xavi Ribas, and Shannon S. Stahl, J. Am.

Chem. Soc., 2010, 132, 12068. 3. Nobumasa Kitajima and Yoshihiko Moro-oka, Chem. Rev., 1994, 94,737

IN-10


45

Peculiarities of Ni, Co, P, Si and Ge split-vacancy defects formation in diamond.

Magnetic and optical properties of the split-vacancy defects

V.A. Nadolinny,1 A.Yu. Komarovskikh,

1 Yu.N. Palyanov

2

1A.V. Nikolaev’s Institute of Inorganic Chemistry SBRAS, Pr. Lavrent’eva 3,Novosibirsk 630090, Russia,

2Institute of Geology and Mineralogy SBRAS, Pr. Koptuga 3, Novosibirsk, 630090, Russia

E-mail:[email protected]

For many years there was an opinion that only light atoms H, N, B could be incorporated into

the diamond structure. This opinion was supported by the fact that the bond length between above

atoms and carbon atom were comparable or less than the length of the C-C bond. Also negative

results were obtained on ion implantation and thermal diffusion of heavy impurity atoms. Only

development of growth technique with nickel and cobalt used as catalysts resulted in the measured

incorporation of heavy atoms (Ni, Co) into the diamond lattice. EPR data on the HTHP diamonds

grown at temperature 1400oC in the nickel containing system showed that the nickel ions occupied

the position of a carbon atom, the electron spin of resulting nickel-containing defect being S=3/2.

According to the fact that Ni-C bond length is ~2Å, the distortion of the diamond structure around

such defect occurs. At high-temperature annealing the stress around such defect can be relaxed by

shifting one of the neighboring carbon atoms to the interstitial position. Thus nickel atom is

displaced towards the vacancy and the split-vacancy structure with octahedral environment around

nickel atom is formed. Distance between Ni and C atoms in such defect is ~2Å, which corresponds

to the desired lengths of the Ni-C bond. Annealing of diamond crystals at temperature of nitrogen

diffusion (above 1600oC) leads to the capture of nitrogen impurity atoms by the split-vacancy nickel

or cobalt containing defects.

Different defects can be observed when the impurity phosphorus atoms are incorporated into

the diamond lattice. For diamonds grown at temperature 1600oC EPR spectra of single nitrogen and

phosphorous atoms at carbon sites are observed. Increase of the annealing temperature of diamond

crystals leads to the aggregation of phosphorus and nitrogen atoms up to close N-P pair in the

adjacent carbon positions. Only at annealing temperature above 2000oC the environment around the

phosphorus atom is changing from tetrahedral to octahedral. The aggregation of nitrogen and

phosphorus atoms is the main reason of the absence of n-type conductivity in the phosphorus doped

HTHP diamond crystals as the substitutional nitrogen is an acceptor of phosphorus electron. In the

case of a high concentration of phosphorus impurity (the concentration of phosphorus impurity is

many times higher than concentration of nitrogen impurity), phosphorus donor levels (0.6 eV)

appeared, which are responsible for the n- type conductivity. In recent years, interest in the defects

with split-vacancy structure in diamond has increased, which is due to the discovered remarkable

magnetic and luminescence properties of split-vacancy defects.

At the end of the 90's the defect thought to be the most promising in quantum information

processing was NV center in diamond, but today the emphasis in quantum technology field has

shifted to the silicon-vacancy and germanium-vacancy centers, having the split-vacancy structure.

In this report the formation of split-vacancy impurity defects was discussed, as well as peculiarities

of their electronic states as incorporated impurity atoms have unfilled d- and p- electron shells, and

potential of split-vacancy defects as a promising systems for different quantum applications.

Acknowledgements:

This work was supported by Russian Science Foundation under grant No. 14-27-00054.

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46

Electron spin resonance spectroscopy using NV centers in diamond

Susumu Takahashi

Department of Chemistry and Department of Physics and Astronomy

University of Southern California, Los Angeles, CA 90089, USA

[email protected]

Magnetic resonance (MR), such as nuclear magnetic resonance (NMR) and electron spin

resonance (ESR), can probe the local structure and dynamic properties of various systems, making

them among the most powerful and versatile analytical methods. However, their intrinsically low

sensitivity precludes MR analyses of samples with very small volumes; e.g., more than 1010

electron spins are typically required to observe ESR signals at room temperature. A vast

improvement in the current limits of MR will enable the imaging of structures and conformational

changes of molecules in solution at the single molecule level.

A nitrogen-vacancy (NV) center in diamond is a promising candidate for applications in room

temperature magnetic sensing with single spin sensitivity. In this presentation, we discuss nanoscale

ESR spectroscopy using a single nitrogen-vacancy (NV) center in diamond. We perform NV-based

ESR using double electron-electron resonance (DEER) technique. By comparing the experimental

result with simulation, we estimated the number of the detected spins to be ≤ 50 spins [1]. We also

carry out measurements of free-induction decay and spin echo decay of a single NV center to study

static and dynamic properties of spins surrounding the NV center. The experiment was also

performed with several other single NV centers in the same diamond sample and showed that the

properties of the bath spins are unique to the NV centers. Moreover, we will discuss development of

a high-frequency NV-based ESR system [2].

References: 1. C. Abeywardana, V. Stepanov, F. H. Cho and S. Takahashi, arXiv:1507.08744. 2. V. Stepanov, F. H. Cho, C. Abeywardana and S. Takahashi, Appl. Phys. Lett. 106, 063111 (2015).

Acknowledgements:

This work is supported by National Science Foundation (USA) and the Searle Scholar program.

IN-12


47

Huge (giant) magnetic anisotropy in nickel(II) complexes revisited -

semiempirical versus ab initio modeling of zero-field splitting

Czesław Rudowicz,1,2

Muhammed Açıkgöz3 and

Paweł Gnutek

4

1 Visiting Professor: Faculty of Chemistry, A. Mickiewicz University, 61-614 Poznań, Poland

2 On leave of absence from: Inst. of Phys., West Pomeranian Univ. of Technology, Szczecin, Poland

3Bahcesehir University, Faculty of Art and Sciences, Beşiktaş, Istanbul, Turkey

4Institute of Physics, West Pomeranian University of Technology, Szczecin, Poland


The zero field splitting (ZFS) of transition ions in crystals means the splitting of the spin levels

within the ground orbital singlet due to the action of the physical Hamiltonian, including the crystal

field (CF) and the spin-orbit coupling (SOC) [1,2]. It is described by an effective spin Hamiltonian

(SH) acting within its own subspace of states of the effective spin operator [2]. Magnetic

Ni2+

(S=1) systems with the axial ZFS parameter (ZFSP) |D| not exceeding 10 cm-1

have attracted

considerable interest due to intriguing behavior [3]. In search of single-molecule magnets [4], huge

(giant) magnetic anisotropy (MA) have been reported in Ni2+

systems [5]. High-magnetic field, high-

frequency EMR (HMF-EMR) study on [Ni(Me6tren)Cl]-(ClO4) yields Dexpt = -120 to -180 cm-1

.

Modeling of ZFS by the density functional theory (DFT) codes confirms D-values: -100 to -200

cm-1

[5a]. HMF-EMR study of [Ni(MDABCO)2 Cl3]ClO4 yields fitted D-values: -350 to -535 cm-1

,

whereas simultaneous fits of susceptibility and magnetization give D = -311 cm-1

[5b]. The D-value

was associated [5a] with the energy between the Ms = ± 1 and Ms = 0 states within the ground state S =

1. The ZFS was ascribed [5b] to the d-orbital splitting for high-spin Ni(II) and Jahn–Teller symmetry-

lowering distortions, so no modeling of ZFS has been carried out in [5b].

The origin of the observed splitting [5], relative role of CF vs. SOC, and appropriateness of

quantifying it in terms of the true ZFSPs D and E (rhombic) seem not clear. Such huge D-values

appear unusual in view of moderate |D|-values of several tens of cm-1 observed in most Ni2+

(S=1)

systems [1]. The DFT methods utilized in [5a] pose an inherent risk of misinterpretation of the

wavefunctions describing the ground spin levels, which are supposed to exhibit such huge splitting.

As in many magnetism papers, also in [5] the MA or single-ion anisotropy (SIA) is equated with

true ZFS, which constitutes the MA=ZFS confusion [2]. Question arises whether the observed or

DFT-calculated huge splitting [5] really represents the true ZFS described by an effective SH [1,2].

To resolve the origin of the splitting, mislabeled as 'huge MA' [5], and obtain better insight into

spectroscopic and magnetic properties of these Ni(II) complexes, we employ semiempirical

methods. Our approach combines superposition model (SPM) [6] calculations of ZFSPs and,

independently, of CF parameters followed by diagonalization of the Hamiltonian (Hfree ion + HCF)

[6]. 6 This study provides clear physical picture in terms of the energy levels and corresponding

wavefunctions, complementary to the DFT results [5a]. The energy levels and states of highly and

slightly distorted Ni(II) complexes have been predicted for various sets of physical parameters and

structural models. Some models and parameter sets reveal exotic arrangements of the lowest energy

levels and states, which require careful analysis to discern the 'ZFSPs' representing computer

S~

IN-13



48

artifacts in outputs [6]. Preliminary results taking into account the Jahn-Teller distortions revealed

by DFT geometry optimization [5a], indicate that the magnitudes of the splitting between the

ground and first excited state match the observed splitting as well as D-signs [5], whereas the states

compositions allow for the true ZFS description [1,2,6].

References:

1. R. Boča, Coord. Chem. Rev. 248 (2004) 757; R. Boča, Struct. Bond. 117 (2006) 1 and references therein. 2. C. Rudowicz and M. Karbowiak, Coord. Chem. Rev. 287 (2015) 28 and references therein 3. C. Rudowicz, Physica B 436, 193-199 (2014) and references therein 4. D. Gatteschi, R. Sessoli, J. Villain, Molecular Nanomagnets, Oxford Univ. Press, 2006 5. a) R. Ruamps, et al., J. Am. Chem. Soc. 135 (2013) 3017; b) K.E.R. Marriott, et al., Chem. Sci. 6 (2015) 6823 6. P. Gnutek, Z.-Y. Yang, and C. Rudowicz, J. Phys.: Condens. Matter 21 (2009) 455402

Acknowledgements:

CZR & PG acknowledge the Polish National Science Center research grant DEC-2012/04/M/ST3/00817.


49

Magnetic Field Effect on the Photocarrier Dynamics in Swallow-Tailed Perylene

Bisimide Derivative: Experimental and Computational Studies

Christopher Ambe,1,2

Yusuke Wakikawa,3 Shiki Yagai,

4 Tadaaki Ikoma

5,6

1Department of Chemistry,

2MSU-IIT Collaborative Research Opportunities in Materials Chemistry,

MSU-Iligan Institute of Technology, Iligan City 9200, Philippines

3Advanced Instrumental Analysis Center, Shizuoka Institute of Science and Technology, 2200-2 Toyosawa,

Fukuroi, Shizuoka 437-8555, Japan 4Graduate School of Engineering, Chiba University, Chiba 263-8522, Japan

5Graduate School of Science and Technology,

6Center for Instrumental Analysis,

Niigata University, Niigata 950-2181, Japan


Swallow-tailed perylene tetracarboxylic acid bisimide (referred herein as STPBI) and other PBI

derivatives are interestingly appealing to many researchers due to their good thermal and

photochemical stability [1] leading to their important applications in organic light-emitting diodes

(OLED), organic field effect transistor (OFET), and organic photovoltaic cell (OPV) [2]. Because

generation of triplet exciton is known to contribute in the enhancement of photocharge in organic

devices [3] and the triplet lifetime in PBI was reported to be considerably long (ca. 100 μs) [4], the

study of carrier dynamics in STBI is deemed important especially that PBIs can be functionalized

strategically [5]. More importantly, previous reports on the magnetic field effect in the photocharge

signal in organic semiconductors [6-8] revealed that time-resolved magnetophotoconductance

(MPC) measurement is a powerful tool to study photocarrier dynamics including that of triplet

exciton interactions. Hence, in this paper, we applied the MPC technique in thin films of pure

STPBI and STPBI-doped poly(N-vinylcarbazole) in order to probe the accessibility of triplet

exciton and the mechanisms governing the interaction of triplet exciton within the organic

semiconductor films. Observed two types of MPC effects indicate the detrapping of the trapped

carriers in STPBI (referred as triplet-doublet (TD) pair mechanism) and also the non-geminate

recombination process (referred as doublet-doublet pair mechanism). Theoretical calculations using

density matrix formalism on the TD pair also reproduce the observed MPC. All experiments and

calculations are done at room temperature.

References:

B. Jancy, S.K. Asha, J. Phys. Chem. B, 2006, 110, 20937-20947. A.Wicklein, et al., J. Am. Chem. Soc., 2009, 131, 14442-14453. A.A. Rachford, S. Goeb, F.N. Castellano, J. Am. Chem. Soc., 2008, 130, 2766-2767. W.E. Ford, P.V. Kamat, J. Phys. Chem. 1987, 91, 6373. F. Würthner, Chem. Commun., 2004, 1564-1579. Y. Wakikawa, T. Ikoma, Y. Yamamoto, T. Fukushima, T. Aida, Synth. Met., 2010, 160, 275-279. C.E. Ambe, Y. Wakikawa, T. Ikoma, Bull. Chem. Soc. Jpn., 2013, 86, 1051-1058. T. Omori, Y. Wakikawa, T. Miura, Y. Yamaguchi, K. Nakayama, T. Ikoma, J. Phys. Chem. C, 2014, 18,

28418-28424.

Acknowledgements:

The authors would like to thank Ministry of Education, Culture, Sports, Science and Technology, CREST grant of

Japan Science and Technology Agency, the Cooperative Research Program of Network Joint Research Center for

Materials and Devices, MSU-Iligan Institute of Technology and Niigata University for partial financial support.

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50

Excited Triplet States of Some Molecules Showing Thermally

Activated Delayed Fluorescence

Tadaaki Ikoma1,2

1Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-

2181, Japan 2Center for Instrumental Analysis, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan


Organic electroluminescence has been studied extensively

with the goal of realizing thin, stable display devices with fast

responses and wide viewing angles. [1]

In organic light-emitting

diodes (OLEDs), the spin statistics determines the population

ratio between the singlet and triplet encounter pairs of electrons

and holes (1,3

e-h). If the encounter pairs have an equal

recombination yield to excitons, then the branching ratio of the

singlet and triplet excitons becomes 1:3. Therefore, the internal

quantum efficiency (IQE) for fluorescent OLEDs is limited to 25

%, the so called singlet-triplet bottleneck. Such spin statistics in

the e-h pair limits the external quantum efficiency (EQE) for

fluorescent OLEDs. Therefore harvesting of the non-radiative

triplet states (triplet harvest) generated at room temperature by

carrier recombination is an important issue for the development of high-efficiency fluorescent OLEDs. In

recent years, thermally activated delayed fluorescence (TADF), which is caused by a reverse intersystem

crossing (ISC), has attracted attention as a high-efficiency technology for OLEDs. The utilization of TADF

from the lowest excited singlet (S1) state with strong charge-transfer (CT) character reported recently by

Adachi et al. is a prospective way to achieve triplet harvest.[2-7] Technology based on TADF may achieve a

100 % IQE without the need for rare metals, in contrast to phosphorescence technology. However, to realize

TADF technology, it is important to experimentally elucidate the kinetics and the electronic structures of the

low-lying excited states. In particular, ISC between the singlet and triplet excited states is a key dynamic of

the TADF mechanism. In this paper, we will present electron paramagnetic resonance (EPR) spectra of the

lowest excited triplet (T1) state for several TADF molecules and discuss both the mechanism of ISC from the

S1 state to the T1 state at low temperature, which still prevails under room temperature, and the electronic

structure of the T1 state.[8]

References:

1. Oh, C.-H.; Shin, H.-J.; Nam, W.-J.; Ahn, B.-C.; Cha, S.-Y.; Yeo, S.-D. In International Symposium Digest of of Technical Papers; Display, S. f. I., Ed.; Wiley: 2013; Vol. 44, p 239-242.

2. Adachi, C. Jpn J. Appl. Phys. 2014, 53, 060101. 3. Endo, A.; Sato, K.; Yoshimura, K.; Kai, T.; Kawada, A.; Miyazaki, H.; Adachi, C. Appl. Phys. Lett. 2011, 98,

083302. 4. Tanaka, H.; Shizu, K.; Miyazaki, H.; Adachi, C. Chem. Commun. 2012, 48, 11392-11394. 5. Uoyama, H.; Goushi, K.; Shizu, K.; Nomura, H.; Adachi, C. Nature 2012, 492, 234-240. 6. Serevicius, T.; Nakagawa, T.; Kuo, M.-C.; Cheng, S.-H.; Wong, K.-T.; Chang, C.-H.; Kwong, R. C.; Xia, S.; Adachi,

C. Phys. Chem. Chem. Phys. 2013, 15, 15850-15855. 7. Huang, S. P.; Zhang, Q. S.; Shiota, Y.; Nakagawa, T.; Kuwabara, K.; Yoshizawa, K.; Adachi, C. J. Chem. Theory

Comput. 2013, 9, 3872-3877. 8. Ogiwara, T.; Wakikawa, Y.; Ikoma, T. J. Phys. Chem. A, 2015, 119, 3415-3418.

IN-15


51

EPR-active molecular pH probes at a protein-lipid interface: an assessment of

local electrostatic effects

Tatyana I. Smirnova, Matthew Donohue, Maxim A. Voynov, Alex I. Smirnov

North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27606, USA


The ionization states of individual amino acid residues of membrane proteins are difficult to

decipher or assign directly in the lipid-bilayer membrane environment. The effective pK(a) values

of protein groups are determined by a complex interplay between local polarity, Coulomb

interactions, and structural reorganizations. The analysis is further complicated by the dearth of

information about gradients in polarity, electric potentials, and hydration at the protein-membrane

interface. In this work we report on developing pH-sensitive ionizable EPR labels and related

methods to 1) profile a heterogeneous dielectric environment along the α-helix of a WALP peptide

integrated in a lipid bilayer and 2) asses the effect of anionic lipid surface charge density on

effective pK(a) of membrane-burred ionisable sidechains and 3) asses the effect of solid state

support on effective pK(a) of membrane-burred ionisable sidechains The change in the protonation

state of the pH-sensitive nitroxide was directly observed by EPR. Displacement of the EPR probe

upon protonation, similar to that of the “snorkeling” of the charged sidechains of Lys and Arg, was

directly observed by DEER and was shown to depend strongly upon the depth of the label with

respect to the bilayer surface. Further, it was found that the experimentally observed dielectric

constant at the membrane-protein interface is significantly higher than the values expected for the

same location in the bulk membrane. The effects of the membrane surface charge density on the

dielectric profile at the peptide-membrane interface and on “snorkeling” of the charged nitroxide

sidechains was investigated. We have also shown that the effective pK(a) of the probe increases by

2.1 to 2.3 pK(a) units (depending on the depth of the probe) upon replacing zwitterionic PC lipids

with anionic PG lipids, with almost 80% of that pK(a) shift is observed upon replacing only half of

the PC lipid with PG lipids. Water penetration at the peptide-membrane interface was assessed by

HYSCORE.

Acknowledgements:

This work is supported by NSF grants 0843632 and 1508607 to T.I. Smirnova.

IN-16


52

Combining Spin-labeling EPR, Solid-state NMR and Site-directed DNP for

Structure Determination of Oligomeric Proteins in Lipid Bilayer Membranes

Sergey Milikisiyants,1 Maxim A. Voynov,

1 Shenlin Wang,

2 Rachel Munro,

3 Matthew Donohue,

1 Leonid

S. Brown,3 Tatyana I. Smirnova,

1 Vladimir Ladizhansky,

3 Alex I. Smirnov

1

1North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27606, USA

2Beijing Nuclear Magnetic Resonance Center and College of Chemistry and Molecular Engineering, Peking

University, Beijing, People’s Republic of China 3Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario,

Canada


Many membrane proteins are known to interact and form stable complexes essential for

carrying out vital cellular functions. Oligomeric structures are also very common. The structure of

membrane protein and their oligomers could be affected by detergents and even chemistry of

specific lipids, thus, making them particularly difficult to study. Here we describe how spin-labeling

EPR methods and DEER in particular provides for determination of the oligomeric order and

obtaining intermonomer distance restraints for an integral membrane protein Anabaena Sensory

Rhodopsin (ASR) reconstituted in the lipid environment using essentially the same preparation of

spin-labeled ASR samples as employed in paramagnetic relaxation enhancement (PRE) NMR

experiments. Magnetic dilutions as well as experiments with model lipid vesicles have been carried

out to improve deconvolution of the DEER signal arising from defined spin clusters from the one

due to random spin-pairs. Further, we show that the oligomeric order can be determined from the

direct modeling of the multispin effects. The later approach could be useful when the efficiency of

spin-labeling is not known with sufficient accuracy. Such an approach allows for an unambiguous

differentiation of the ASR trimers from other types of symmetric oligomers. We then combine long-

range DEER data with NMR restraints to refine ASR structure: addition of long-range

intermonomer DEER restraints to the previously determined short- and medium-range NMR

restraints resulted in a more compact packing of helices and refined positions of side chains at the

intermonomer interface compared to the structure determined using the NMR data alone. Further

enhancements in NMR sensitivity were achieved using a newly synthesized biradical, ToSMTSL

(Totapol Series MethaneThiosulfonate Spin Label), which is based on the known DNP agent

TOTAPOL, but also contains a thiol-specific methanethiosulfonate group to allow for incorporating

this biradical into a protein in a site-directed manner. ToSMTSL was tested for DNP of a

heptahelical transmembrane protein, Anabaena Sensory Rhodopsin (ASR), by covalent

modification of solvent-exposed cysteine residues in two 15N-labeled ASR mutants. The use of

covalently attached biradicals to proteins and lipids would broaden the applicability of DNP NMR

to structural studies of proteins and membrane protein systems.

IN-17

ORALPRESENTATIONS


53

Field modulated pulsed EPR

Mark Tseytlin,1,2,3

Boris Epel,2 Subramanian Sundramoorthy,

2

Dmitriy Tipikin,1,3

and Howard J. Halpern2

1 Department of Biochemistry, School of Medicine, West Virginia University, Morgantown, West Virginia,

USA. 2 Center for EPR Imaging In Vivo Physiology, Department of Radiation and Cellular Oncology, University

of Chicago, IL, USA; 3 In vivo Multifunctional Magnetic Resonance center, Robert C. Byrd Health Sciences Center, West Virginia

University, Morgantown, WV, USA


Excitation power in pulsed EPR exceeds that generated by the spins by many orders of

magnitude. As a result, the detector must be protected during and immediately after the pulse. The

protection constitutes the instrumental dead-time. Decoupling of the excitation from the detection is

achieved either in time, as in the spin echo experiment, or in space by using orthogonal bi-modal

resonators 1,2

. A higher degree of decoupling can be achieved in the frequency domain. The

excitation and detection coils can be tuned to different frequencies. To ensure resonance conditions

for both coils, sinusoidal magnetic field modulation that changed the Larmor frequency of the spins

during free evolution can be used. Because the field modulation is constantly affecting the spin

precession, the measured signals demonstrate transient effects similar to those observed in rapid

scan EPR 3. Transformation into the reference frame associated with the changing Larmor

frequency of the spins is needed to restore the ‘normal’ echo shape.

References:

1. Rinard GA, Quine RW, Biller JR, Eaton GR. 2010 A Wire Crossed-Loop-Resonator for Rapid Scan EPR. Concepts Magn Reson Part B Magn Reson Eng;37B(2):86-91.

2. Sundramoorthy SV, Epel B, Halpern HJ. 2014 Orthogonal resonators for pulse in vivo electron paramagnetic imaging at 250 MHz. J Magn Reson;240:45-51.

3. Tseitlin M, Rinard GA, Quine RW, Eaton SS, Eaton GR. 2011 Deconvolution of sinusoidal rapid EPR scans. J Magn Reson;208(2):279-83.

Acknowledgement:

The support of this work by NIH K25 EB016040, NIH/NIGMS U54GM104942, EB002034 and CA98575 are

gratefully acknowledged. The content is solely the responsibility of the authors and does not necessarily represent the

official views of the National Institutes of Health.

OR-01



54

Improved setup for force-detected ESR measurement

using fiber-optic interferometry

Hideyuki Takahashi,1 Tsubasa Okamoto,

2 Eiji Ohmichi

2 and Hitoshi Ohta

3

1Organization for Advanced and Integrated Research, Kobe University, Kobe 657-8501, Japan

2Graduate School of Science, Kobe University, Kobe 675-8501, Japan

3Molecular Photoscience Research Center, Kobe University, Kobe 657-8501, Japan


Micro-cantilever is a very sensitive force sensor. It has been used not only as a probe for atomic

force microscope, but also as a tool for magnetization measurement. It has an advantage over the

SQUID magnetometer in that it can be used under high magnetic field. Nowadays, its application is

extended to high-frequency electron spin resonance spectroscopy (HFESR)[1,2].

The accuracy of cantilever magnetometry depends on the methods to detect the deflection 𝛥𝑑.

There are various detection methods such as piezoresistive, capacitive, and optical interferometric

detection. Among them, optical interferometric detection is the most sensitive. By measuring the

interference intensity 𝐼 of Fabry-Perot cavity formed between the cantilever and the cleaved end of

an optical fiber, one can detect 𝛥𝑑 with a sensitivity of smaller than 10 pm [2]. However, since 𝐼

changes against 𝛥𝑑 in a sinusoidal manner, it is not easy to measure the large deflection in real-

time. It is one of reasons why piezoresistive cantilevers have been preferred for the use under high

magnetic field [1].

In this study, we present the method

to broaden the dynamic range of optical

detection of cantilever deflection. The

key idea is to use wavelength-tunable

laser source (see Figure). The

wavelength 𝜆is proportional-integral

controlled to keep 𝐼 constant during

measurements. The change in 𝜆 is

proportional to 𝛥𝑑. Using this

technique, we can measure the large

deflection (𝛥𝑑 > 𝜆) without degrading

sensitivity. We applied this technique to

HFESR measurement and succeeded in

removing the nonmonotonic background

which arises from the constantly varying

sensitivity of the interferometer.

References:

1. H. Takahashi, E. Ohmichi and H. Ohta, “Mechanical detection of electron spin resonance beyond 1 THz”, Appl.

Phys. Lett. 107, 182405 (2015).

2. E. Ohmichi et al., “Multi-frequency force-detected electron spin resonance in the millimeter-wave region up to 150

GHz”, submitted.

Acknowledgements:

This research was partly supported by a Grant-in-Aid for Young Scientists (B) (16K17749), Grants-in-Aid for Scientific

Research (B) (Nos.22340101 and 26287081) and by a Grant-in-Aid for Challenging Exploratory Research (No.

26610104) from JSPS, and by the Canon Foundation.

Figure. The improved experimental setup for cantilever ESR measurement.

OR-02


55

Pulsed Dipolar EPR on Cu(II) and Co(II) ions

Angeliki Giannoulis, Katrin Ackermann and Bela E. Bode

EaStCHEM School of Chemistry, Biomedical Sciences Research Complex and Centre of Magnetic

Resonance, University of St Andrews, Scotland


Pulsed electron electron double resonance (PELDOR) or synonymously double electron

electron resonance (DEER) is a pulsed EPR technique widely applied in structural biology for

obtaining distance constraints and thus gaining information on biomacromolecular stuctures and on

their conformational changes. [1] Electron spins, e.g. nitroxide spin labels, for PELDOR application

in these systems can be chemically introduced via site-directed spin labelling techniques. There are

also cases where paramagnetic metal ions, like Cu(II) and Co(II) occur naturally in the system and

could be used in metal-based pulsed EPR distance measurements [2] for tackling challenging

systems. Furthermore, paramagnetic metal ions can, in principle, be used as spin tags e.g. the

double histidine (dHis) – Cu(II) binding motif. [3]

Here, Cu(II) and Co(II) PELDOR performance is studied on mixed metal(M)-nitroxide(NO)

systems, with the NO moiety being the terminal part of a terpyridine-based ligand. Together with

the M-NO distances, information was gained on the binding affinity of the ligand to the

corresponding metal centre. [4] Spectral overlap of the NO and M species could be solved by means

of a filter pulse. [5]

Relaxation Induced Dipolar Modulation Enhancement (RIDME) spectroscopy is an emerging

single frequency pulsed EPR technique suitable for measuring M-M and M-NO distances. [6] In

this work RIDME is employed to study the M-NO distances.

References:

1. C. Pliotas, R. Ward, E. Branigan, A. Rasmussen, G. Hagelueken, H. Huang, S. S. Black, I. R. Booth, O. Schiemann, J. H. Naismith, Conformational state of the MscS mechanosensitive channel in solution revealed by pulsed electron–electron double resonance (PELDOR) spectroscopy, Proc. Natl. Acad. Sci. USA, 2012 (109) E2675–E2682

2. D. Abdullin, N. Florin, G. Hagelueken, O. Schiemann, EPR based Approach for the Localization of Paramagnetic Metal Ions in Biomolecules, Angew. Chem. Int. Ed., 2014 (53) 1–6

3. T. F. Cunningham, M. R. Putterman, A. Desai, W. S. Horne, S. Saxena, The double-histidine Cu²⁺-binding motif: a highly rigid, site-specific spin probe for electron spin resonance distance measurements, Angew. Chem. Int. Ed. Engl. 2015 (54) 6330-6334

4. K. Ackermann, A. Giannoulis, D. B. Cordes, A. M. Z. Slawin, B. E. Bode, Assessing Dimerisation Degree and Cooperativity in a Biomimetic Small-molecule Model by Pulsed EPR, Chem. Commun., 2015 (51) 5257–5260

5. T. Maly, T. F. Prisner, Relaxation filtered hyperfine spectroscopy (REFINE), J. Magn. Reson., 2004 (170) 88–96 6. V. Astashkin, Mapping the Structure of Metalloproteins with RIDME, Methods Enzymol., 2015 (563) 251–284

OR-03



56

Application of millimeter wave gyrotron to pulsed ESR measurement

S. Mitsudo, K. Hiiragi, M. Narioka, C. Umegaki, Y. Fujii

Research Center for Development of Far-Infrared Region, University of Fukui,

Fukui,Bunkyou 3-9-1, Japan


The pulsed ESR method has advantage of measuring relaxation times of electron spins as

compared to CW ESR method. One of the most popular pulsed methods is spin echo method, in

which subsequent two pulses (/2 and pulses) with a delay time are applied to a sample and the

echo signal is obtained after another time from the end of the second pulse. In general, a pulsed

ESR spectroscopy requires a certain pulse duration, then it determines the required strength of

the microwave PRF as ~ PRF-1

. The higher power means the shorter , which extends the

applicability of pulsed ESR methods. To date, the commercial pulsed ESR systems at X-band have

been used extensively by researchers. The system with millimeter and/or submillimeter wave region

is thought to be more useful. However, its development includes many difficulties in the treatment

and development of high power radiation sources. Gyrotron is a high power radiation source in the

submillimeter wave region [1-3], which is suitable for the radiation source of a short-pulsed ESR

system. The radiation of several kW from a high power gyrotron allows the pulse duration in

nanosecond-order. Such system has a potential to develop materials sciences, especially in the

subject of substance with short relaxation time.

As the high power millimeter wave source, a CW operated sub-THz Gyrotron (Gyrotron FU

CW VIIA) has been developed. We examined many candidate modes and finally selected a TE02

mode (154 GHz, 150 W). In order to obtain a Gaussian mode electromagnetic wave beam from a

TE02 mode, a quasi-optical mode converter was developed. A radius of 9 mm beam waist was

obtained at the semiconductor shutter system. This liner polarized millimeter wave beam is incident

on Si wafers with an incident angle made to a Brewster angle. In order to realize the intense and

short excitation millimeter wave pulses by using a Gyrotron output, a high power millimeter wave

pulse forming system (PFS) has been developed by using light controlled semiconductor shutters. A

quasi-optical transmission system has been developed to be led these short pulses to ESR

measurement probe. The quasi-optical transmission line has advantages such as a good maintaining

liner polarization, low power transmission loss for millimeter and submillimeter wave region. This

quasi-optical transmission line is consisted of three characteristic parts. The Gaussian beam

properties of short pulses from a PFS are converted into the form suitable for the long distance

transmission in a matching optics unit I (MOU-I). After then, short millimeter pulses are transmitted

through a quasi-optical transmission line (QOT) which is consisted of four elliptical mirrors and

four flat mirrors and converted into beam waist size suitable for coupling to the ESR probe which is

consisted of a corrugated circular wave guide in a MOU-II. MOU-II also has the function as a

switcher and a duplexer. Therefore, we can use pulsed wave from a gyrotron for the pulsed ESR and

CW wave from a vector network analyzer for CW ESR. Output from ESR probe is reflected to

different direction by rotating wire grid and transmitted to detection system.

References

1. T. Idehara, I. Ogawa, S. Mitsudo, M. Pereyaslavets, N. Nishida and K. Yoshida, IEEE Transactions on Plasma Science, 27, (1999) 340-354.

2. S. Mitsudo, T. Higuchi, K. Kanazawa, T. Idehara, I. Ogawa and M. Chiba, J. Phys. Soc. Jpn., Suppl. B, 72, (2003) 172-176.

3. S. Mitsudo, H. Hoshizuki, T. Idehara and T. Saito, Journal of Physics: Conference Series, 51, (2006) 549-552.

OR-04


57

Improving Signal-to-Noise in EPR

Igor Gromov and Peter Höfer

Bruker BioSpin GmbH, Silberstreifen 4, Rheinstetten, 76287, Germany


One of the main drivers for new developments in EPR is the demand for higher signal-to-noise.

With a number of recent product introductions we have made significant progress in this field.

The high power Q-Band pulse-EPR setup allows running DEER experiments with dramatically

improved sensitivity, e.g. the measurement time of 22h in X-Band is reduced to 25min in Q-Band,

thus increasing sample throughput by more than a factor of 50. To achieve this, a combination of a

high power pulse amplifier (150 W) and a large volume resonator are used allowing short inversion

pulses of 10 ns at 150 MHz resonator bandwidth.

Limitations in excitation bandwidth are a severe handicap in pulse-EPR. The availability of

high speed arbitrary waveform generators allows new methods in EPR based on pulse shaping for

larger bandwidth excitation. With shaped broad band inversion pulses the DEER modulation depth

can be improved by a factor 2 – 3 and HYSCORE spectra can be measured with much higher S/N.

An ongoing project for a very significant gain in S/N is the development of a rapid scan unit.

First results and specifications will be reported.

For a commercial instrument all technological advances have to be combined with a strong

focus on usability. This is exemplified by the recently introduced EMXnano bench-top spectrometer

which features full instrument calibration with respect to field and signal amplitude, dedicated

workflows and requires only little technical knowledge of the user.

OR-05


58

Binding structure of the extrinsic subunit PsbP of photosystem II

revealed by PELDOR

Hiroyuki Mino,1 Mizue Asada,

1,2 Taishi Nishimura,

3 Fumihiko Sato,

3 Kentaro Ifuku

3

1Graduate School of Science, Nagoya University Furo-cho, Chikusa, Nagoya, 464-8602, Japan

2Department of Materials Molecular Science, Institute for Molecular Science, Nishigo-Naka 38, Myodaiji,

Okazaki, 444-8585, Japan

3Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606–8502, Japan.


Photosystem (PS) II protein complex is a catalyst of the photosynthetic oxygen evolution. The

main reaction center of PS II is well conserved in species, however, the extrinsic subunits have

variety depending on the species. PsbP is an extrinsic subunit of PS II in higher plants and

maintains oxygen-evolving activity of PS II. The molecular structure of PS II isolated from

cyanobacteria has been revealed by recent X-ray structural analysis, however, the binding site and

topology of PsbP in PS II are still unknown. In this study, the location of the PsbP in PS II complex

was revealed by pulsed electron-electron double resonance (PELDOR).

MSL spin labels were introduced to the four residues of the Cys-introduced PsbP mutants.

Each MSL-labeled PsbP mutant was reconstituted to a PS II whose extrinsic subunits had been

depleted in pretreatment. The stable tyrosine radical YD• in PS II core complex was formed by

illumination. We measured the distances between YD• and MSL-labeled moieties of PsbP by

PELDOR. The distance between YD• and the center of PsbP was calculated as 45.5 Å based on the

PELDOR results, and is similar to the distance of 46.5 Å between the YD• and the center of PsbV of

cyanobacteria obtained from the crystal structure [1]. The location of PsbP in PS II was determined

assuming that the basic amino acid patch of PsbP directly binds to CP43 subunit as revealed by the

cross-linking evidences [2]. The topological information was consistent with the mobility of the

spin labels at the Cys-introduced sites in PsbPs obtained by CW-EPR spectroscopy. The interaction

between PsbP and the oxygen evolving complex will be further discussed.

References:

1. Suga M. et al., Nature, 2015, 517, 99-103. 2. Nishumura T. et al., Biochim. Biophys. Acta, 2014, 1837, 1447-1453

OR-06


59

Trilateration and orientation selection DEER measurements on human carbonic

anhydrase type II

Maxim Yulikov,1 Luca Garbuio,

1 Kaspar Zimmermann,

2 Elisa Nogueira,

2 Guido Grassi,

1

Thomas R. Ward,2 Daniel Häussinger,

2 Gunnar Jeschke

1

1ETH Zurich, Laboratory of Physical Chemistry, Vladimir Prelog Weg 2, 8093 Zürich, Switzerland

2Basel University, Department of Chemistry, Klingelbergstr 80, 4056 Basel, Switzerland


The active site of the human carbonic anhydrase II (hCA II) can be inhibited with a variety of

sulfonamide-based compounds capable of binding to the protein’s Zn(II) center with high affinity.

In this work we utilize this property to prepare orthogonally spin labeled hCA II mutants by using a

cysteine mutation and thiol-specific reaction to site specifically attach Gd(III)-based spin label at

one of four selected positions, and a nitroxide radical derivative of a sulfonamide inhibitor to

introduce the second, non-identical type of spin label at the binding pocket. We use a particular type

of lanthanide chelate complex1 specially designed for the best performance in the NMR pseudo-

contact shift (PCS) measurements, and demonstrate its applicability in the Gd(III)-Gd(III) and

nitroxide-Gd(III) double electron-electron resonance (DEER) experiments. In particular, we report

on the trilateration of the nitroxide radical position, as well as on the measurement of the nitroxide

ring orientation based on the Q-band (35 GHz) DEER measurements. A newly constructed rotamer

library for this Gd(III)-based spin label is used to predict the spin-spin distance distributions. These

predictions are compared to the experimental DEER data and to the positions of the lanthanide ions

derived from the PCS experiments. Finally, we discuss the perspective of using DEER and PCS in

hybrid structure determination approaches. We acknowledge financial support of the Swiss National

Science Foundation.

References: 1. D. Häussinger, J. Huang, S. Grzesiek, J. Am. Chem. Soc. 131 (2009), 14761−14767.

OR-07


60

Electronic Structure of the Excited Triplet State of Hexaphyrins with twisted

Möbius Conformation As Studied by Time-resolved EPR

Fumitoshi Ema,1 Shohei Saito,

2 Atsuhiro Osuka,

2 Mana Tanabe,

3 Seigo Yamauchi,

3 Kenji Sugisaki,

4

Kazunobu Sato,4 Takeji Takui,

4 Takashi Tachikawa,

1 Yasuhiro Kobori

1

1Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan

2Graaduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho,

Sakyo-ku, Kyoto 606-8502, Japan 3Institute of Multidiscipnary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira,

Aoba-ku, Sendai 980-8577, Japan 4Graaduate School of Science, Osaka City University, 3-3-138 Sugimoto,

Sumiyoshi-ku, Osaka 558-8585, Japan


Expanded porphyrins have attached great attentions in terms of the aromaticity, functional dyes,

non-linear optical materials, and stable radicals.1 Möbius aromatic molecules are thus regarded as

promising functional materials. [26]- and [28]hexaphyrins have been treated as a comparable set of

aromatic/antiaromatic congeners both in the ground state and in the excited states.2 Twisted Möbius

[28]Hexaphyrins have experimentally exhibited the Möbius antiaromaticity in the lowest excited

triplet state whereas the Möbius aromaticity in the ground state.3 However, the relationship between

the antiaromaticity and the electronic structures has not been clarified in the excited triplet state. In

this study, the electronic structures of the excited triplet states of the planar [26]- and the twisted

Möbius [28]Hexaphyrins have been investigated using an X-band time-resolved EPR (TREPR)

method combined with magnetophotoselection (MPS) measurements.

Meso-hexakis (pentafluorophenyl) [26]Hexaphyrin (1.1.1.1.1.1) and Meso-hexakis

(pentafluorophenyl) [28]Hexaphyrin (1.1.1.1.1.1) ([26]Hex and [28]Hex) were dissolved in 2-

Methyltetrahydrofuran and toluene. These solutions were sealed in the sample tubes after the

freeze-pump-thaw cycles to remove the dissolved oxygen molecules. The TREPR measurements

were performed at 77 K with using a nanosecond-pulsed OPO laser at 568 nm and 650 nm pumped

by the 355 nm Nd:YAG laser system. In the MPS experiments, the excitation laser polarization (L)

was set parallel and perpendicular to the external magnetic field direction (B0).

TREPR spectra of [26]Hex and [28]Hex at 77 K showed the fine structures by the spin-spin

dipolar coupling of the excited triplet states. From the MPS effects on the TREPR spectra, the

principal axes orientations in the dipolar interactions were determined with respect to the transition

dipole moments. The zero field splitting (ZFS) parameters D, E and |E/D| obtained for [28]Hex

were different from those for [26]Hex. The EPR parameters analyzed by the molecular orbital

calculations suggested that the spin-density is not uniformly delocalized in the twisted Möbius

[28]Hex macrocycle in the lowest excited triplet state, in contrast to highly delocalized distribution

in the planar [26]Hex macrocycles. For the excited triplet state in the twisted Möbius [28]Hex, the

sign of D was determined to be negative from the anisotropy in the S1-T1 intersystem crossing

(ISC). The intramolecular charge-transfer character has been revealed to play a role on the

anisotropy in the T1-S0 ISC, and are consistent with the molecular orbital calculations.

References:

1. S. Saito, et al, Angew. Chem. Int. Ed., 2011, 50, 4342-4373. 2. Y. M. Sung, et al, Nat. Chem., 2015, 7, 418-422. 3. J. Oh, et al, Angew. Chem. Int. Ed., 2016, in press.

OR-08


61

Generation and Dissipation of Spin Polarization in the Excited Quartet State of

Vanadyl Porphyrins

Motoko S. Asano,1 Tsubasa Asami,

2 Yoshifumi Yasuda

1 and Art van der Est

3

1Division of Molecular Science, School of Science and Engineering, Gunma University,

Tenjin-cho, Kiryu, Gunma 376-8515, Japan 3Department of Chemistry, Tokyo Metropolitan University, Hachi-Ohji, Tokyo 192-0397, Japan 3Department of Chemistry, Brock University, 500 Glenridge Ave. St. Catharines Ont., Canada


Vanadyl(V(IV)O) porphyrin exhibits luminescence in the wide range of temperature. This

luminescence is dominantly of porphyrin triplet emission character and shows large temperature

dependence. The lowest excited state of VO porphyrin is the quartet state, where a doublet spin in

vanadyl ion and the triplet spin of porphyrin -electron system are coupled. The doublet state,

which is composed of the same vanadyl doublet and porphyrin triplet states, is present upper the

lowest quartet state. An energy gap ( E ) between the quartet and doublet state is supposed to be

several tens cm-1

and dynamics involving the excited doublet and quartet states is considered as the

origin of the temperature dependence. However, the detailed mechanism has not been explored.

Time-resolved EPR spectroscopy is expected to elucidate relaxation mechanism of the excited state

dynamics not only from viewpoint of spin dynamics but also from that of electronic relaxation. In

this work, based on substituent dependence as well as temperature dependence on time-resolved

EPR signals, we present generation and dissipation mechanism of spin polarization in the excited

quartet state in relation to the decay rates of luminescence of VO porphyrin.

Vanadyl tetrakis(pentafluorophenyl)porphyin (TFPPVO) has different porphyrin peripheral

substitunents from octaethylporphyrin complex of which time-resolved EPR was reported as a first

example of excited species of paramagnetic metal complexes[1]. Different substituents lead to a

different energy gap between the doublet and quartet states, E. This is because peripheral

substituents sensitively change electron density of the porphyrin HOMO orbital and thus exchange

interaction between the vanadyl unpaired electron and porphyrin electron changes. For three VO

porphyrins studied in this work, TREPR spectra at 12 K were

composed of multiplet and net absorptive spin-polarization patterns.

However, amplitudes as well as relaxation rates of multiplet

signals greatly depend on peripheral substituents. Based on

temperature dependence of luminescence as well as that of net

absorptive TREPR signals, E values were estimated. For a VO

porphyrin with a smaller E, multiplet signal is less intensive and

decays faster. Mechanism which accounts for the relation between E

and TREPR signal behaviors is proposed.

1. Kandrashkin, Y. E.; Asano, M. S.; van der Est, A. Phys. Chem. Chem. Phys. 2006, 8, 2129–2132.

Fig.2 TREPR spectra of

TFPPVO at 12K excited at

540nm Fig.1 Energy diagram of VO porphyrins and structure of TFPPVO

A

E

OR-09


62

Electron Spin Polarization Study of Charge Separated States

in Molecular Triads Centered by Aluminum Porphyrin

Yuri E. Kandrashkin,1 Prashanth K. Poddutoori

2 and Art van der Est

2

1Zavoisky Physical-Technical Institute, Russian Academy of Sciences,

Sibirsky Tract 10/7, Kazan, Russian Federation 2Department of Chemistry, Brock University,

1812 Sir Isaac Brock Way, St. Catharines ON, L2S 3A1 Canada


The ability of aluminum(III) porphyrin (AlPor) to form axial bonds provides a convenient way

of assembling donor-acceptor complexes and influence the electronic coupling between the

porphyrin and the attached donors and acceptors. The triads are constructed by covalently linking

the acceptor to the Al(III) metal center and coordinating pyridine-appended tetrathiafulvalene (TTF)

on the opposite face of the porphyrin. Using a variety of acceptors and different solvents, long-lived

light-induced charge separation can be achieved in these complexes [1].

Here, we report on transient EPR studies of the charge-separated states of the triads with two

different types of acceptors, free-base porphyrin (H2Por) and anthraquinone (AQ). The observed

spin polarization patterns allow us to estimate the exchange interactions of the observed states and

to clarify the ET pathways for direct and reverse transitions. The results of the investigations will be

discussed.

References:

1. Yu. E. Kandrashkin, P.K. Poddutoori, A. van der Est, Appl. Magn. Reson. 2016, 47, 511–526

Acknowledgements:

The work was partially supported by the program of the Physical Sciences Department of RAS.

OR-10


63

Overhauser DNP properties of phosphonated trityl probe: dependence of signal

enhancement on probe exchange parameters

Andrey A. Bobko, Benoit Driesschaert, Valery V. Khramtsov

In Vivo Multifunctional Magnetic Resonance center, Robert C. Byrd Health Sciences Center and Department

of Biochemistry, West Virginia University, Morgantown, WV 26506, United States

Overhauser-enhanced magnetic resonance imaging (OMRI) has found application for detection

of oxygen1, acidity

2 and redox status

3 in in vivo experimental set ups. It was shown that Overhauser

signal enhancement of proton DNP spectra (or MRI images) strongly depends on nitroxide probe

concentration with Heisenberg self-exchange of spin probe playing an important role in

enhancement build-up4. Oxygen concentration also affects the signal enhancement of trityl probes

due to spin exchange between these two paramagnetic molecules. It has been shown that oxygen

and probe concentrations can be extracted using two consecutive image acquisitions5. Recently an

application of nitroxide and trityl probes for detection of pH using OMRI were reported2, 6

.

Here we present a study of phosphonated trityl probe OMRI signal enhancement under

different exchange conditions: (i) spin exchange with oxygen molecules; (ii) spin self-exchange;

and (iii) chemical exchange, namely buffer-facilitated proton exchange. Obtained results are used

for evaluation of the number of images sufficient to assess oxygen, proton (pH) and inorganic

phosphate concentrations simultaneously in in vivo cancer model experiments.

References:

1. Krishna, M.C., et al., Proc Natl Acad Sci U S A, 2002. 99(4): p. 2216-21. 2. Bobko, A.A., et al., Magnetic Resonance in Medicine, 2012. 67(6): p. 1827-1836. 3. Kosem, N., et al., Free Radical Biology and Medicine, 2012. 53(2): p. 328-336. 4. Turke, M.-T., et al., Physical Chemistry Chemical Physics, 2012. 14(2): p. 502-510. 5. Efimova, O.V., et al., Journal of Magnetic Resonance, 2011. 212(1): p. 197-203. 6. Takahashi, W., et al., Applied Magnetic Resonance, 2014. 45(9): p. 817-826. Acknowledgements:

This work was partially supported by NIH grants CA194013, CA192064 and U54GM104942. The content is solely the

responsibility of the authors and does not necessarily represent the official views of the NIH.

OR-11


64

In vivo mapping of protease activity using Overhauser-enhanced MRI:

challenges and promises

Gérard Audran,2 Paul Brémond,

2 Jean-Michel Franconi,

1 Neha Koonjoo,

1 Sylvain Marque,

2 Philippe

Massot,1 Philippe Mellet,

1 Elodie Parzy,

1 Eric Thiaudière

1

1Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536

CNRS-Université de Bordeaux, France 2Institut de Chimie Radicalaire, UMR 7273 CNRS-Université Aix Marseille, France


The recent developments of imaging techniques provides opportunities to increase the ability to

visualize in vivo biological processes in intact organisms.

Among atraumatic molecular imaging strategies, OMRI/PEDRI has shown its potential to

underline and target specific activities such as pH linked activities and tissue redox processes [1-2].

The principle is to prompt through a double resonance experiment the polarization transfer from an

unpaired electron of a free radical to surrounding water protons.

This method has been used at 0.2 T to locate in vivo proteolysis in mice. For this purpose an

EPR cavity operating at 5.43 GHz was inserted in an open MRI system (8.24 MHz NMR

frequency). Pulsed EPR-MRI sequences including a keyhole fully balanced steady-state free

precession sequence was used to generate 3D images within only 20 seconds and with a spatial

resolution of 500 um in each direction.

In a first step proteolysis was detected with a nitroxide-labeled elastin [3]. In the absence of

proteolysis the rotational correlation time of this macromolecule was too high to generate narrow

EPR lines, thus preventing efficient DNP. After digestion into rapidly tumbling fragments the

decrease in correlation time was suitable for OMRI detection. Normal intestinal digestion of the the

nitroxide-labeled elastin was thus revealed after oral gavage, with signal enhancements of around

7.

In a next step, our collaborators synthesized a beta-phosphorylated nitroxide substrate. This

molecule was exhibiting a acetyl to ketone conversion upon enzymatic hydrolysis leading to a

variation of the phosphorus hyperfine coupling constant of around 4 G. The presence of either the

substrate or the product was assessed by tuning the EPR cavity to the desired frequency. During in

vivo OMRI experiment after gavage of living mice with this probe, the signal enhancement was

first detected in the stomach when the EPR cavity was tuned at 5.4257 GHz (substrate) and

disappeared over time. Conversely signal enhancement increased at 5.4175 GHz EPR frequency

(product) upon hydrolysis by stomach enzymes.

These studies highlight the great potential of our OMRI approach in the field of Molecular

Imaging in detecting proteolytic activity. Combined with a specific molecular probe, this tool is

efficient and robust. It can be used to target more specific enzymes to evaluate unregulated

proteolytic activities in various models of experimental diseases and for drug testing.

References:

1. M.C. Krishna, S. English, K. Yamada , J. Yoo, R. Murugesan, N. Devasahayam, J.A. Cook, K. Golman, J.H. Ardenkjaer-Larsen, S. Subramanian, J.B. Mitchell, Proc Natl Acad Sci U S A, 2002, 99(4), 2216–2221.

2. W. Takahashi, A.A. Bobko, I. Dhimitruka, H. Hirata, J.L. Zweier, A. Samouilov, and V.V. Khramtsov, 2014, Applied Magnetic Resonance, 45.9, 817–826.

3. E. Parzy, V. Bouchaud, P. Massot, P. Voisin, N. Koonjoo, D. Moncelet, J.M. Franconi, E. Thiaudière, P. Mellet, 2013, PLoS ONE, 8.2, e57946.

Acknowledgements

This work received the financial support from the French National Agency (ANR) in the framework of the Investments

for the Future, within the TRAIL Cluster of Excellence (ANR-10-LABX-57)

OR-12



65

Investigation of a Tetracycline-binding RNA aptamer by using

ELDOR-detected NMR

Thilo Hetzke,1 Alice Bowen,

1 Marc Vogel,

2 Beatrix Suess,

2 Thomas Prisner

1

1Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438

Frankfurt am Main, Germany 2Department of Biology, TU Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany


ELDOR detected NMR (EDNMR) is a pulsed EPR method to detect hyperfine couplings. It

was pioneered by Schweiger and co-workers in 1994 [1]. EDNMR uses two microwave

frequencies; one fixed frequency (νdet) to observe an allowed EPR transition and another variable

frequency (νELDOR) to excite forbidden transitions of the type ΔmS = ±1 and ΔmI = ±1, ±2,... When

νELDOR matches the frequency of a forbidden transition, population is removed from one nuclear

spin manifold and the intensity of the echo detected at νdet is decreased.

EDNMR is more sensitive than ENDOR, especially for the detection of nuclei with a low

gyromagnetic ratios. It is even possible to observe natural abundance 13

C signals [2]. However, due

to the spectral blind spot, caused by excitation of the observed allowed EPR transition by the

ELDOR pulse as νELDOR approaches νdet,

most EDNMR studies probing nuclei with

low gyromagnetic ratios have been carried

out at ≥ 95 GHz, where the Larmor

frequencies of nuclei are higher and

therefore the signals are not obscured by the

central blind spot [3].

In this study we have used EDNMR to

detect hyperfine couplings from 1H,

13C,

17O,

31P and

55Mn at Q-band (34 GHz) for

Mn2+

centered spin systems. The technique

was used to investigate the interaction of Mn2+

with the antibiotic Tetracyline (TC) and a TC-

binding aptamer. In the presence of the aptamer, two distinct 31

P couplings are indicative of an

interaction of Mn2+

with the phosphate groups of the RNA backbone (data shown in figure). In

order to study the correlations of different nuclei (e.g. 13

C and 31

P) to the same coupled electron spin

(Mn2+

) the EDNMR pulse sequence was expanded into a second frequency domain – an experiment

recently reported by Kaminker et al. (2D-EDNMR) [4]. We demonstrated the principle of a 2D-

EDNMR on the [Mn(H2O)6]2+

/[Mn(H217

O)6]2+

model system, before using 2D-EDNMR to study the

binding of TC to the TC-aptamer by comparing the intensities of the 13

C/31

P-crosspeaks of an

aptamer sample with labelled TC to a sample with unlabeled TC.

References:

1. P. Schosseler, T. Wacker, A. Schweiger, Chem. Phys. Lett., 1994, 224, 319-324. 2. E. Bruch, M. Warner, S. Thomine, L. Tabares, S. Un, J. Phys. Chem. B, 2015, 119, 13515-13523. 3. N. Cox, W. Lubitz, A. Savitsky, Mol. Phys., 2013, 111, 2788-2808. 4. I. Kaminker, T. Wilson, M. Savelieff, Y. Hovav, H. Zimmermann, Y. Lu, D. Goldfarb, J. Mag. Reson., 2014, 240,

77-8.

Figure 1: EDNMR data collected on different Mn2+

systems. Spectra have been inverted and the blind spot

subtracted. Signals in the region ±25 to ±15 MHz

correspond to 31

P couplings and the signals at ±13 MHz

are due to 13

C couplings.

OR-13


66

Development of High-Frequency Magnetic Resonance System for DNP

Measurements at Very Low Temperatures

Y. Ishikawa,1 K. Ohya,

2 S. Miura,

2 Y. Fujii,

3 S. Mitsudo,

3 T. Mizusaki,

3 H. Kikuchi,

2 A. Fukuda,

4 A.

Matsubara,5 S. Lee,

6 H. Yamamori

3 and S. Vasiliev

7

1Advanced Interdisciplinary Science and Technology, University of Fukui, Fukui 910-8507, Japan

2Department of Applied Physics, University of Fukui, Fukui 910-8507, Japan

3Research Center for Development of Far-Infrared Region, Univ. of Fukui, Fukui 910-8507, Japan

4Department of Physics, Hyogo College of Medicine, Nishinomiya 663-8501, Japan

5Research Center for Low Temperature and Materials Sciences, Kyoto Univ., Kyoto 606-8501, Japan

6Department of Physics, Korea Advanced Institute of Science and Tech., Daejeon 305-701, Korea

7Wihuri Physical Laboratory, Department of Physics and Astronomy,

University of Turku, 20014 Turku, Finland


Dynamic nuclear polarization (DNP) induced by electron spin resonance (ESR), where a high

electron spin polarization is transferred to nuclear polarization through the hyperfine interaction, is

a powerful technique to enhance the sensitivity of nuclear magnetic resonance (NMR)

measurements. One typical example of DNP was found in lightly phosphorous-doped silicon (Si:P)

more than 50 years ago [1]. Up to now, however, it is difficult to observe 31

P-NMR signal directly

because the critical concentration of P atoms to keep Si:P in a insulator region is too low. Further,

since a quantum computer (QC) design using Si:P proposed by Kane [2], which is one of the best

practical QC designs, requires high magnetic fields (a few Tesla) and low temperatures in the range

of 100 mK in order to quench degree of freedom of electron spins, it becomes intriguing to study

spin dynamics including DNP phenomena of Si:P in mK region. Recently, Järvinen and co-workers

have performed extensive high-frequency ESR studies with a 3He/

4He dilution refrigerator (D/R)

and demonstrated 31

P nuclear polarization higher than 98 % [3,4].

We have been developing an ESR/NMR double resonance system

on a D/R which enables us to perform DNP-NMR and ENDOR

measurements to investigate 31

P spin dynamics.

In this paper, we will report current status of our

development and ESR measurements with DPPH and MnxMg1-xO

(x = 10-4

). We have constructed a homodyne-detection ESR

system as shown in Fig. 1. The sample is put in a Fabry-Perot

type cavity (FPC) which is used to increase the irradiation power

on the sample. ESR measurements of DPPH and MnxMg1-xO (x =

10-4

) have been performed at 127.8 GHz in the temperature down

to 0.09 K under a magnetic field 4.6 T. The sensitivity of ESR

was around 1013

spins/gauss, being high enough to detect ESR

signal from Si:P in a low dopant concentration range. We have

also tested a new FPC made of thin gold (< 1 µm) in order to put

NMR coil across the FPC since such a thin metal layer is

transparent for RF while reflective for mm-wave.

References: 1. A. Abragam, The Principles of Nuclear Magnetism (Clarendon, Oxford, 1961). 2. B. E. Kane, Nature 133, 393 (1998). 3. J. Järvinen et al., Phys. Rev. B 90, 214401 (2014). 4. J. Järvinen et al., Phys. Rev. B 92, 121202 (2015).

Fig. 1: Block diagram of ESR system on D/R

OR-14


67

Using SDSL-EPR spectroscopy to characterize the structural details of

membrane proteins

Lu Yu,1 Li Zhou,

2 Ying Xiong,

2 Changlin Tian

1

1 High Magnetic Field Laboratory, Hefei institutes of Physical Science, Chinese Academy of Sciences, Hefei,

Anhui, 230031, P. R. China. 2 School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, P. R. China

Site-Directed Spin-Labelling Electron Paramagnetic Resonance spectroscopy (SDSL-EPR) has

emerged as a powerful method for studying the structure and conformational dynamics of proteins,

especially large membrane proteins under conditions relevant to function. It yields information

about the nitroxide side chain mobility, solvent accessibility, and the distance between the nitroxide

and another paramagnetic center in the protein, which is further interpreted to characterize protein

topography and to determine orientations of individual segments of the protein.

Here, we introduce the application of SDSL-EPR in our laboratory to study several membrane

proteins, including integrin beta1, E. coli integral membrane sulfurtransferase YgaP and human

Interferon-inducible transmembrane protein IFITM3, with specific focus on the different types of

information which can be obtained with continuous wave and pulsed techniques. Continuous Wave

(CW) EPR studies revealed distinctively different motional properties and oligomeric states of TM

region of integrin beta1, namely a monomer embedded in detergent micelles and leucine-zipper-like

homo-oligomeric clusters in liposomes. EPR-based hybrid experimental and computational

approaches were applied to determine the structure of a full-length E. coli integral membrane

sulfurtransferase, dimeric YgaP, and its structural and dynamic changes upon ligand binding, which

provides insight into the thiocyanate exportation mechanism of YgaP in the E. coli membrane.

SDSL-EPR spectroscopy and solution NMR studies were conducted to characterize the structural

topology of human IFITM3 protein, supporting the mechanism of an enhanced restricted membrane

hemi-fusion.

A. Schematic models of the integrin beta1-TM in detergent micelles or in liposomes; B.

Hypothetical conformational changes of YgaP upon substrate(SCN-) binding; C. Schematic model

of IFITM3 in the membrane

References: 1. Yu, L., W. Wang, et al. (2015). Sci Rep 5: 7848. 2. Ling, S., W. Wang, et al. (2016). Sci Rep 6: 20025. 3. Ling, S., C. Zhang, et al. (2016). Sci Rep 6: 24029.

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68

EPR Investigation of Conformational Changes in Annexin 12 upon

Membrane Interaction

Balachandra G. Hegde1 and Ralf Langen

2

1Department of Physics, Rani Channamma University, Vidyasangama, PBNH-4, Belagavi 591 156,

Karnataka India. 2Department of Biochemistry and Molecular Biology, Zilkha Neurogenetic Institute, University of Southern

California, Los Angeles, California 90033


Annexins are soluble proteins that exhibit Ca2+

-dependent membrane surface binding. In

addition to Ca2+

- dependent membrane interaction, annexin 12 (Anx12) undergoes pH -dependent

membrane interaction as well. Such interaction (pH <6.5; dependent on lipid composition) causes

large-scale conformational changes without significantly altering the overall percentage of helical

structure. Several lines of evidence suggest that, at pH =4, Anx12 takes on a transmembrane

structure with ion channel activity. For example, a previous site-directed spin labeling (SDSL)

analysis of a helical hairpin (residues 138 to 158) in solution suggests the formation of a single

transmembrane helix at pH = 4. Based upon sequence analysis and additional SDSL data, we

predict that several other hairpin regions could fold inside out and behave similarly. In order to

better understand the conversion of a helix-loop-helix structure in solution into a continuous

transmembrane helix, we investigated the pH -dependence of the conformational changes in the

138-158 region for different lipid compositions. Using site directed spin labeling (SDSL) in

conjunction with CW EPR , we determined the immersion depth of three single-cysteine mutants of

Anx12 located on the lipid-facing surface of the transmembrane helix formed between pH = 4 to pH

= 6.5. We found that the immersion depth of those residues decreased as pH increased. Together

with membrane leakage data and other results, we interpret these data in terms of equilibrium

between multiple membrane-bound states. That is, in addition to the transmembrane form, Anx12

appears to be capable of taking on a membrane interfacial form that is helical, yet unrelated to the

solution or Ca2+

-dependent surface-bound form as shown in the following model.

Figure: Model showing the pH dependent binding of Anx12 to cardiolipin membrane. After inside out refolding

the 138-158 region goes from surface bound form to transmembrane form.

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In-cell protein structures from single 2D-NMR experiments using lanthanide

chelating tags suitable for PCS-NMR and EPR studies

Daniel Häussinger,1 Thomas Müntener,

1 Francois-Xavier Theillet,

2 Philipp Selenko,

3

Maxim Yulikov,

4 Gunnar Jeschke

4

1Basel University, Department of Chemistry, St. Johannsring 19, 4056 Basel, Switzerland

2Department of Structural Biology, Institute of Integrative Biology of the Cell (I2BC) – UMR 9198,

CNRS/CEA/Paris-Saclay University, CEA Saclay Bât. 144, 91191 Gif-sur-Yvette, France 3Department of Structural Biology, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert

Roessle Str. 10, 13125 Berlin, Germany 4ETH Zurich, Laboratory of Physical Chemistry, Vladimir Prelog Weg 2, 8093 Zürich, Switzerland


Lanthanide chelating tags (LCTs) that can be conjugated site-specifically to cystein sulfhydryl

functions on the surface of proteins are valuable tools for both EPR and NMR spectroscopy. We

have recently developed a rigid, high affinity LCT based on the well-known

DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) scaffold,

but decorated with eight stereo-specifically attached methyl groups, termed

DOTA-M8 and have demonstrated its outstanding properties for both

EPR[1] and pseudo contact shift (PCS) NMR[2]. The unusual rigidity of

DOTA-M8 is reflected in a very narrow distribution of metal positions

relative to the protein, which allows more precise distance and angle

determination in EPR and NMR experiments.

Here we would like to report on our in-cell NMR experiments with a

new, closely related LCT displaying seven methyl groups and one pyridine substituent as well as a

phenyl-sulphone activator function (Fig.1). By exploiting the PCSs and residual dipolar couplings

(RDCs) generated from thulium loaded Tm-DOTA-M7Py

conjugated to 15N labelled protein G B1 domain (GB1) and

injected into intact Xenopus laevis oocytes, we were able to

determine for the first time a protein structure inside a living

eukaryotic cell. Remarkably, the structure could be elucidated

using only very sensitive and fast (5-10 h) 2D-NMR experiments at near physiological in-cell

protein concentrations (50 µM). We calculated 3 sets of 10’000 structures in the Rosetta program

without experimental NMR data, with addition of

PCS restraints and with both, PCS and RDC data.

Fig.3 shows the excellent agreement of the lowest energy confor-

mations (red) with the GB1 structure (PDB code: 2PLP) obtained

by conventional 3D-NMR in vitro data.

References:

1. L. Garbuio, K. Zimmermann, D. Häussinger, G. Jeschke, M. Yulikov, J. Magn. Reson., 2015, 259, 163-173. 2. D. Häussinger, J. Huang, S. Grzesiek, J. Am. Chem. Soc., 2009, 131, 14761-7. 3. Th. Müntener, D. Häussinger, Ph. Selenko, F.-X. Theillet, submitted.

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Humic Substances as Matrixes for Obtaining of The Silver-Containing

Bionanocomposites with Antioxidant Activity

Spartak S. Khutsishvili,1 Nikolay I. Tikhonov,

1 Marina V. Lesnichaya,

1 G. Dolmaa,

2 Tamara I.

Vakul’skaya,1 Galina P. Aleksandrova,

1 Boris G. Sukhov

1

1 Irkutsk Institute of Chemistry of the SB of RAS, Irkutsk, Russia

2 Chemistry and Chemical Technology Institute of MAN, Ulaanbaatar, Mongolia


Substances of humic series are widely distributed on the planet [1], and have found wide,

multi-faceted application in engineering, agriculture, environmental protection, industrial additives,

cosmetics and pharmacy, veterinary, and medicine [2], as well as new opportunities in other areas

are opening. They are natural biological compounds, their pharmacological properties are due to the

content of bioactive substances of humic series. However, the structure of humic compounds is

extremely difficult and the diversity of their properties is still not well understood. Especially,

obtained silver-containing nanocomposites, longterm aggregative stable bionanocomposites with

constant properties based on humic substances from medicinal mud, having magnetic properties,

arouse great interest. Whereas, this unique magnetic properties are shown in nanoscale state [3]. All

studied silver-containing nanocomposites, as well as their starting matrices, showed the high

antioxidant activity, the value of which exceeds that of the known antioxidant - succinic acid.

It was surprisingly found in the EPR spectrum that the investigated nanocomposites based on

humic substances of Mongolian sources give a multicomponent signal from several lines with a

binomial splitting, careful analysis of which has shown that it corresponds to the generated silver

nanoclusters (Agn). Silver reduction to the zero valent state are most likely due to oxidizable

aldehyde, and phenolic groups located in considerable amounts in the composition of humic

substances. However, it should be noted, that free radicals along with phenolic groups playing the

role of a reducing agent of metal ions can coordinate them and stabilize the nanoparticles of the

latters. The formation of regular stable ultrasmall metal particles, especially, in natural compounds

with complex structure is a quite rare phenomenon and opens new ways for the study of not only

the magnetic properties at the nanoscale, but enriches the information on natural nanochemistry, and

allows to plunge deeper into unique structure of the humic substances. The use of modern methods

(including pulse-EPR) allows to uncover an intramolecular structure of complex natural molecules,

to build the most probable path of the metal reduction and stabilize it in the matrix, to find the

environment around the formed cluster, and to determine the packaging and ordering of structural

fragments around these areas, preventing further agglomeration clusters.

References: 1. Lehmann J., Kleber M., Nature 528, 60-68 (2015). 2. Klöcking R., Helbig B., Medical aspects and applications of humic substances. In: Biopolymers for medical and

pharmaceutical applications. Steinbüchel A, Marchessault RH, Wiley-VCH, Weinheim, 3-16 (2005). 3. Lesnichaya M.V., Aleksandrova G.P., Dolmaa G., Sapozhnikov A.N., Sukhov B.G., Regdel D., Trofimov B.A.,

Dokl. Chem. 456, 72-75 (2014).

Acknowledgements: This work was supported by the President Grant of Russian Federation (Grant MK-7149.2016.3).

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Magnetite Nanoparticles Reorganization in Ferroarabinogalactan in The

Process of Thermal Degradation

Nikolay I. Tikhonov, Spartak S. Khutsishvili, Tamara I. Vakul’skaya,

Galina P. Aleksandrova, Boris G. Sukhov

Irkutsk Institute of Chemistry of the SB of RAS, Irkutsk, Russia


Magnetic nanocomposite materials with metal particles are widely used in modern electronics,

solar cell production, in biology, the preparation of catalysts, medicines and others. Among received

nanosubstances special interest biocompatible nanocomposites based on a variety of

polysaccharides, and in particular, arabinogalactan (AG), received from siberian larch, with a

complex of catalytic, magnetic, optical and biological - antimicrobial, immunomodulatory and

cytotoxic properties. Unusual magnetic, in particular paramagnetic, and thermostable properties of

the nanocomposites largely determine their uniqueness and wide application.

It was made the study of thermal stability of multifunctional iron composite based on the

natural polysaccharide AG and iron oxides and their paramagnetic properties change with

temperature. We have shown that the magnetite nanoparticles of Fe3O4, being coated with a shell of

natural high molecular polymer, form aggregate stability of magnetic nanomaterials.

Nanocomposites study was performed in a linear temperature rise process by the methods of DTA

and TGA to 600°C, and by EPR to 400°C. The results indicate that the nanocomposites have a

temperature resistance up to 200°C. EPR method shows that all composites to some extent possess

ferromagnetic properties at room temperature, which was confirmed by measurements of their

magnetization. The similar nature of the FMR spectra investigated nanocomposites, which are

asymmetric broad absorption lines, shows small changes in size and shape of the resulting

nanoparticles with varying iron content in the nanocomposite from 3.5 to 6.4%. The greatest change

in the magnetic properties of iron-containing nanomaterials associated with changing the particle

size decreases. Even a slight variation of the method for manufacturing nanocomposites leads to a

heterogeneous particle chemical composition and changes in their magnetic characteristics. FMR

results show a significant anisotropy distribution of nanoparticles, increasing the size of the past and

a possible change of the domain status. The latter is consistent with the appearance of an inflection

point at 6.4% concentration of iron in the dependences gef-factor and the width of the EPR signal,

the parameters of the magnetization and the size of nanoparticles on the percentage of iron content

in the nanocomposite and the detected magnetic activity relationship to the size and shape of the

nanoparticles. Trends destruction ferroarabinogalactan observed directly in the EPR spectrometer

resonator and were compared with the TGA and DTA. The EPR characteristics of change of g-

factor and linewidth signal showed the presence of critical points on reaching 200°C – thermal

degradation of the nanocomposite. Introduction of magnetite nanoparticles in polysaccharide matrix

greatly lowers the activation energy of thermal degradation process, thereby reducing the

degradation of the nanocomposite temperature range compared to the initial polysaccharide. On

exotherm effect in ranging 220-290°C due to the thermal degradation of AG, superimposed very

intense effect in the temperature interval 290-390°C, due to oxygen diffusion in the structure of the

samples and oxidation of iron oxide (II), which is part of the magnetite. Prolonged storage

nanocomposites bounded by external impact has shown that metal nanoparticles exist stably in the

matrix, at least for one year, while maintaining the unchanged EPR characteristics.

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72

Fig. 1 Structure of the samples

Investigation of hyperfine interaction in Cu(II)-bis(oxamidato) complexes by

pulse ED NMR technique

R.B.Zaripov1, E.L.Vavilova1, V. K. Voronkova1, K.M. Salikhov1, A. Aliabadi2, A. Petr2, V. Kataev1,2,

B. Büchner2, M. A. Abdulmalic3, T. Rüffer3

1Kazan E. K. Zavoisky Physical -Technical Institute, Sibirsky tract 10/7, Kazan, 420029, Russia 2Institute of Solid State Research IFW Dresden, Helmholtzstraße 20, Dresden, D-01171, Germany

3Technical University of Chemnitz, Straße der Nationen 62, Chemnitz, D-09107, Germany


It is well known that ELDOR detected NMR (ED NMR) technique as well as ENDOR is useful

instrument to determine hyperfine constants. Often the better results are obtained at high microwave frequencies [1,2]. In this work we present a study of two complexes by the pulse ED NMR technique at Q-band, named as complex P1 and complex P2. The difference between two complexes is in the ligands R. The P1 and P2 complexes contained ethanol and propyl ligands respectively (see Fig.1) [3].

The mononuclear Cu(II)-bis(oxamidato) complexes

have been already demonstrated to be useful precursors for the synthesis of multimetallic complexes with a large structural variability [4]. It has been already shown that EPR studies allow to extract information about the spin population distribution of mononuclear copper(II) bis(oxamato) complexes via the analysis of the hyperfine interaction tensor [5].

We show that pulse ED NMR at the Q-band is a very

promising method to study such kind of systems. It has enabled us to accurately determine the hyperfine interaction parameters of individual nitrogen ligands.

References 1. I. Kaminker et al.: J. Magn. Reson., 2014, 240, 77-89. 2. A. Nalepa et al., J. Magn. Reson., 2014, 242, 203-213. 3. M.A. Abdulmalic et al.: Dalton Trans.,2015, 44, 8062-8079. 4. A.C. Dias, M. Knobel, H. O. Stumpf, J. Magn. Magn. Mater, 2001, 226,1961-1963. 5. B. Bräuer, Inorg. Chem., 2008, 47, 6633-6644. Acknowledgements This work was supported by the Deutsche Forschungsgemeinschaft through project FOR 1154 “Towards Molecular Spintronics”, by the Russian Foundation for Basic Research through project RFBR 14-02-01194, and by the Program of Fundamental Research of the Presidium RAS №26.

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72-B

Magnetic properties of YMnO3 ceramic samples

Rushana M. Eremina,1,2 Ivan V. Yatsyk,1,2 Tatiana P. Gavrilova,1,2 Ildar F. Gilmutdinov,2

Vladimir I. Chichkov,3 Nikolai V. Andreev3

1Kazan E. K. Zavoisky Physical-Technical Institute of the RAS, Sibirsky tract 10/7, Kazan, 420029, Russia 2Kazan (Volga Region) Federal University, Kremlyovskaya st. 18, 420018, Kazan, Russia

3National University of Science and Technology MISiS, Leninskiy prospekt 2, 119991, Moscow, Russia


Polycrystalline samples of yttrium manganites YMnO3 were synthesized according to the standard ceramic technology. The magnetization measurements showed that the phase transition temperature in YMnO3 is T~45K and CW~-445K (Fig. 1 a). ESR measurements were carried out in the paramagnetic regime at the temperature above the phase transition temperature T~45K at the frequency of 9.48GHz. In this temperature range the ESR spectrum of YMnO3 consists of one broad exchange-narrowed resonance line (Fig.1 b). The g-factor of the resonance signal shifts towards to lower fields starting from the value g=2.28 at T=200K and getting the value g=3.05 at T=70K. These values of g-factors are not usual for Mn3+ ions with S=2, so we can suggest the more complicated nature of the signal.

Fig. 1. (a) Temperature dependence of magnetization and inverse magnetic susceptibility of YMnO3; (b) – ESR spectra at different temperatures in YMnO3. Acknowledgements: This work was supported by the programs of the Presidium of the Russian Academy of Sciences no. 26.

0 50 100 150 200 250 300 3500.06

0.08

0.10

0.12

0.14

0.16

M (H=3000Oe)

Mag

netiz

atio

n (e

mu/

g)

T (K)

(a) 20

25

30

35

40

45

1/ =C/(T+445)

1/

(103 g

/em

u)

YMnO3

0 3000 6000 9000 12000 15000

190K170K150K130K110K90K

Inte

nsity

(a.u

.)

H (Oe)

70K

YMnO3

(b)

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73

Distribution of Stable Paramagnetic Species in Apple Seeds Investigated by EPR

and X-band EPR Imaging

Kouichi Nakagawa1 and Boris Epel

2

1Department of Radiological Life Sciences, Graduate School of Health Sciences, Hirosaki University, 66-1

Hon-cho, Hirosaki 036-8564, Japan 2Department of Radiation and Cellular Oncology, The University of Chicago, MC1105, 5841 S. Maryland

Ave, Chicago, IL 60637-1463 USA

[email protected]

We investigated the location and distribution of paramagnetic species in apple seeds were

investigated using electron paramagnetic resonance (EPR) and X-band (9 GHz) EPR imaging

(EPRI) [1-4]. A JEOL (Tokyo, Japan) modified 9 GHz EPR imager was used for EPR and EPR

imaging measurements. The system was operated in X-band mode at 9.43 GHz and 100 kHz

modulation frequency. We used 16 projections obtained with gradients from 0 to ~1.4 mT/cm. Then,

the data were back-projected to obtain a 2D image using

a filtered back-projection algorithm. All measurements

were performed at ambient temperature. The data were

processed in the MathWorks MATLABTM

environment

using EPR-IT software package developed by the Center

for EPR Imaging In vivo Physiology.

EPR showed mainly two paramagnetic species were

observed in a seed. The two different radical species

were assigned to stable organic radicals and Mn2+

complexes. The signal at g = ~2.00 was very strong and

stable. Then, we obtained EPR image of the organic

radical in the seed. The EPRI showed that the stable

radicals were located in the seed coat as shown in Figure 1. Very few radicals were observed in the

cotyledon of the seed. Thus, the present CW EPR and EPRI results suggest that the stable

paramagnetic species were only located in the seed coat and quite few radicals were found in other

seed parts. EPRI and CW EPR are highly useful in evaluating stable radical species and distribution

of radicals in biological samples.

References: Nakagawa K. and Epel B., Spectrochimica Acta Part A, Molecular & Biomolecular Spectroscopy, 2014, 131, 342-346. Nakagawa K. and Hara H., Free Radical Res., 2015, 49, 1-6. Nakagawa K. and Hara H., Proceeding of 7th Biennial Meeting of Society for Free Radical Research-Asia, 2015, 7-16. Nakagawa K. and Hara H., Free Radical Res., 2016, 50, 523-529.

Figure 1. X-band 2D EPR image of apple

seed. The image measurement was

performed at ambient temperature.

2.0 mm

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Solvent effect in Nitroxides: What’s New in 2016

G. Audran,1 P. Brémond,

1 S.R.A. Marque

1,2

1 Aix-Marseille Université, CNRS-UMR 7273, ICR, France

2 Novosibirsk Institute of Organic Chemistry SB RAS, Russia


This talk deals with the development of new nitroxides highly sensitive to the polarity of the

solvent.1 For decades, the nitrogene hyperfine coupling constant aN of nitroxides has been applied to

probe their environment using EPR.

However, the small changes observed (≈ 2 G from n-pentane to water) with the solvent polarity

allow only a qualitative discussion. A stable -phosphorylated nitroxide exhibiting a small

change in aN (≈ 3 G from n-pentane to water) and a striking change in aP (≈ 25 G from n-

pentane to water, 4cA to 4cE, dots on top right figure) with the polarity of solvent was

prepared and used to develop the first procedure for the titration of water in THF by EPR, down to

0.1% v/v (left figure).

References: 1. Audran, G.; Bosco, L.; Brémond, P.; Butscher, T.; Marque, S. R. A. Org. Biomol. Chem. 2016, 14, 1228-1292.

Acknowledgements: Grants: ANR-09-BLA-0017-01 and ANR-11-JS07-002-01

0 % water

0.2 %

0.6 %

1 %

2 %

100 %

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EPR Characterization of Surface Electron-Donor Sites of Pd-Rh/Alumina Three-Way Catalysts

Roman M. Kenzhin1, Alexander M. Volodin1, Vladimir O. Stoyanovskii1, Aleksey A. Vedyagin1,2, Ilya V. Mishakov1,2

1Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva 5, Novosibirsk, 630090, Russia

2Tomsk Polytechnic University, Lenin Avenue 30, Tomsk, 634050, Russia


The use of noble metals supported on oxide supports as catalysts for various chemical

processes is known for a long time. Such materials are used in many modern technological processes. Palladium and palladium-rhodium catalysts are used in neutralizers of exhaust gases in modern automobiles. Nowadays three-way catalysts (TWC) are well-developed materials used in internal combustion engines for simultaneous conversion of unburned hydrocarbons, carbon monoxide (CO) and nitrogen oxides (NOx). A problem of stability of the three-way catalysts is of special importance. It is known that a relatively small loading of the precious metals allows reaching the acceptable activity in such reactions as CO and hydrocarbons oxidation and nitrogen oxides reduction. However, in the course of operating, especially in the long run, a major part of the active component is deactivated, and the remaining amount of active Pd and/or Rh is not enough to provide the required level of the activity of the catalytic composition in general.

To solve the problem of Pd/Rh catalysts deactivation we have used a special approach in that

study: securing the active components as clusters on the electron-donor sites of the support (γ-Al2O3) forming bimetallic Pd-Rh particles, which hinders the transition of Rh into ionic form followed by its diffusion into the bulk. For this purpose, we used the spin probe method for characterization of electron-donor sites on the surface of oxide catalysts possessing basic properties. That technique were developed by us earlier [1-2]. Radical anions of aromatic nitrocompounds (for example, 1,3,5-trinitrobenzene (TNB)) formed after their adsorption on the surface of oxide catalysts were used as spin probes for investigation of the surface electron-donor sites. It was shown that the electron-donor sites of the γ-Al2O3 surface are important for stabilizing the supported palladium in the form of atomic-dispersed ions Pd2+. Both single-metal and bimetallic Pd-containing complexes are stabilized on the same electron-donor sites on the surface of the support. TNB radical anions can be used for characterization of such systems, including their evolution after thermal aging.

References 1. A.A. Vedyagin, A.M. Volodin, V.O. Stoyanovskii, I.V. Mishakov, D.A. Medvedev, A.S. Noskov, Applied Catalysis

B, 2011, 103, 397. 2. A.A. Vedyagin, A.M. Volodin, V.O. Stoyanovskii, R.M. Kenzhin, E.M. Slavinskaya, I.V. Mishakov, P.E. Plyusnin,

Yu.V. Shubin Yu.V., Catalysis Today, 2014, 238, 80. Acknowledgements This study was supported by Russian Foundation for Basic Research (Grant 16-33-00359).

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EPR Characterization of Surface Electron-Acceptor Sites during Catalytic and

Solid-State Reactions

Alexander Bedilo,1,2 Ekaterina Shuvarakova,1,2 Alexander Volodin1

1 Boreskov Institute of Catalysis SB RAS, Pr. Lavrentieva 5, Novosibirsk, 630090, Russia 2 Novosibirsk Institute of Technology, Moscow State University of Design and Technology,

Krasnyi Prospekt 35, Novosibirsk, 630099, Russia


High-silica zeolites and sulfated metal oxides are known to possess exceptionally strong one-electron acceptor sites capable of ionizing compounds with very high ionization potentials, such as benzene (IP = 9.2 eV) [1]. Weaker electron-acceptor sites with electron affinities ~ 7 eV exist in high concentrations on the surface of alumina and some other metal oxides [2]. However, their role in various reactions on the surface of nanocrystalline materials is not understood.

In the current communication an original technique developed for characterization of electron-acceptor sites in the course of catalytic or solid-state reactions will be reported. Correlations between the concentrations of electron-acceptor sites measured during the reactions with the catalytic activity and performance in solid-state destructive adsorption processes will be demonstrated.

Weak electron acceptor sites were found to be formed on the surface of nanocrystalline MgO destructive adsorbents during their solid-state reactions with CF2Cl2. This reaction is characterized by an unusual long induction period [3]. Their activity was observed to correlate with the concentration of weak electron-acceptor sites tested by anthracene or perylene. Similar correlations were observed for CF2Cl2 decomposition over Al2O3, which was found to react with CF2Cl2 at substantially lower temperature due to much higher concentration of electron-acceptor sites.

The catalytic activity of nanocrystalline aerogel-prepared MgO in 1-chlorobutane dehydrochlorination was found to increase significantly during the reaction, which is accompanied by modification of the MgO surface and bulk with chloride ions. A good correlation was observed between the catalytic activity and the concentration of weak electron-acceptor sites. Substantial concentrations of electron-acceptor sites present on Al2O3 surface [2] were found to make this material much more active in catalytic dehydrochlorination.

The experimental correlations between the concentrations of the electron-acceptor sites and the catalytic activity in reactions catalyzed by acids suggest that these reactions are likely to occur on such sites rather than on more abundant traditional acid sites. Such sites also seem to be responsible for some bulk solid-state reactions. EPR appears to be an excellent technique for characterization of such very active surface sites. References: 1. A.F. Bedilo, A.M. Volodin, Kinet. Catal., 2009, 50, 314-324. 2. A.F. Bedilo, E.I. Shuvarakova, A.A. Rybinskaya, D.A. Medvedev, J. Phys. Chem. C, 2014, 118, 15779-15794. 3. A.F. Bedilo, E.I. Shuvarakova, A.M. Volodin, E.V. Ilyina, I.V. Mishakov, A.A. Vedyagin, V.V. Chesnokov, D.S.

Heroux, K.J. Klabunde, J. Phys. Chem. C, 2014, 118, 13715-13725. Acknowledgements: This study was partially supported by Russian Foundation for Basic Research (Project 15-03-08070).

OR-23B


76

S

*IrIII

hvIrIII

S

IrII

X

X

S

S

X

Mechanism Study of Functionalization of Aryl Halides via Visible Light Catalyst

Haijun Yang, Min Jiang, Yong Li

Department of Chemistry, Tsinghua University, Beijing, 100084, China


In recent years, visible light catalyst functionalization of halogentated alkanes has made a big

progress[1]

. But only a few works achieved for the functionalization of aryl halides[2,3]

. And for the

mechanism study, there are mere works to reveal the intermediates of the aryl halides during the

reaction. All reactions need an amine as an electron donor in the former works. However, the

initiation of the reaction was not explained clearly. It is very important to prove the process that the

catalyst provides an electron to the aryl halides or the amine donor does one to the catalyst firstly. In

order to solve this question, thiophenol was used to replace the amine as an electron donor, and

produces a thioether. Because of the simple reaction condition and efficiency, this reaction was

selected to understand the reaction mechanism of visible-light induced functionlization of aryl

halides. In this works, we use DMPO to trap the intermediates existed in the reaction, and EPR to

detect the intermediates. It is found that thiophenol or thiol played a role as an electron donor, and

produce a sulfur radical. An aryl halide anion radical is discovered. Base on this intermediates, a

possible mechanism was proposed (Figure 1).

References:

1. J. M. R. Narayanam, C. R. J. Stephenson, Visible light photoredox catalysis: applications in organic synthesis. Chem. Soc. Rev., 2011, 40, 102-113.

2. I. Ghosh, T. Ghosh, J. I. Bardagi, B. König, Reduction of aryl halides by consecutive visible light-induced electron transfer processes. Science, 2014, 346, 725-728.

3. J. D. Nguyen, E. M. D’Amato, J. M. R. Narayanam, C. R. J. Stephenson, Engaging unactived alkyl, alkenyl and aryl iodides in visible-light-mediated free radical reaction. Nat. Chem., 2012, 4, 854-859.

Figure 1. Possible mechanism of functionalization of aryl halides via visible light catalyst

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77

EPR study of the MOF-based photocatalytic system

Co@NH2-MIL-125(Ti)

M. V. Fedin,1 S. L. Veber,

1 D. Yu. Osadchii,

2 M. A. Nasalevich,

2 R. Becker,

3 E. V. Ramos-Fernandez,

4

S. Castellanos,2 F. Kapteijn,

2 J. N. H. Reek,

3 J. I. van der Vlugt,

3 J. Gascon

2

1International Tomography Center SB RAS. Institutskaya ЗА, Novosibirsk. 630090, Russia

2Catalysis Engineering, Applied Sciences, Delft University of Technology

Julianalaan 136, 2628 BL, Delft, The Netherlands 3Homogeneous, Bioinspired and Supramolecular Catalysis, van't Hoff Institute forMolecular Sciences,

University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands 4Laboratorio de Materiales Avanzados, Departamento de Qu´ımica Inorg´anica-Instituto Universitario de

Materiales, Universidad de Alicante, Ap. 99, E-03080 Alicante, Spain


Metal-organic frameworks (MOFs) nowadays find numerous applications in different fields of

science and technology and belong to the hottest topics in chemistry and materials science. Among

such applications, photocatalysis using MOF-based systems appears highly promising. Of particular

significance is the development of visible light-driven systems catalyzing water splitting and

generating hydrogen for green energy applications. MOFs have been proven to be photoactive and

their optical properties can be easily tuned towards visible light operation. The current challenge

lies in the development of more appropriate active sites for the desired photocatalytic cycle. In our

recent work, a new strategy to achieve this goal has been described [1]. By introducing a derivative

of the well-known molecular Co-based electrocatalyst Co-dioxime-diimine into the pores of a

photo-active NH2-MIL-125(Ti) following a ‘Ship-in-a-bottle’ strategy, we were able to synthesize a

highly active photocatalyst composite free of noble metals, and fully recyclable. The resulting

hybrid system Co@MOF was demonstrated to be a robust heterogeneous composite material.

Furthermore, Co@MOF was found to be an efficient and fully recyclable noble metal-free catalyst

system for light-driven hydrogen evolution from water under visible light illumination.

Electron Paramagnetic Resonance (EPR) study of Co@MOF catalyst allowed us obtain

valuable insights into the mechanism of the photocatalytic activity and hydrogen evolution [1]. An

intense EPR signal centred at g ~1.94 evolved upon irradiation, which was attributed to

paramagnetic TiIII

formed by ligand-to-metal charge transfer. Exposing Co@MOF in reaction

mixture of water, acetonitrile and triethylamine to a visible light for a few hours results in the

gradual rise of a new broad and intense line, which can be assigned to the CoII species. The detailed

analysis of these signals at X- and Q-bands (9/34 GHz) as a function of temperature shows that

most likely these CoII species reside in exchange coupled networks, and possibly involve Ti

III ions

as well in such exchange clusters. Importantly, contrary to the pristine MOF sample, no EPR signal

was detected for a TiIII

species in Co@MOF, which can be assigned to the charge transfer between

the photogenerated charge-separated state in the MOF and cobalt complex encapsulated in MOF, as

well as to the exchange coupling between TiIII

and CoII species. Further studies on active sites

responsible for the high photocatalytic activity of Co@NH2-MIL-125(Ti) composite are underway.

References:

1. M. A. Nasalevich, R. Becker, E. V. Ramos-Fernandez, S. Castellanos, S. L. Veber, M. V. Fedin, F. Kapteijn, J. N. H. Reek, J. I. van der Vlugt, J. Gascon, Energy Environ. Sci., 2015, 8, 364-375.

Acknowledgements

This work was supported by the Russian Science Foundation (No. 14-13-00826).

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78

Single-molecule Electron Spin Resonance spectroscopy by diamond sensor

Fazhan Shi

Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China

E-mail: fzshi(at)ustc.edu.cn

Single molecule science and technology have unique abilities to probe molecular structure,

dynamics and function, unhindered by the averaging inherent in ensemble experiments. Single

molecule science have broadly applications in kinds of scientific research fields, such as chemistry,

physics, biology, material science. Until now, kinds of technology or methods have been developed.

Single-molecule magnetic resonance spectroscopy and imaging is one of the ultimate goals in

magnetic resonance. Different from conversional magnetic resonance methods, we are trying to

push the MR sensitivity to single molecule based on the spin of a single nitrogen vacancy (NV)

center in diamond and explore the applications in different research fields. Firstly, we detect a single

dark electron spin inside diamond[1]. Then, cooperation with biologist, we detected the

spectroscopy of a single protein labeled by nitroxide free radicals[2]. Now, we are trying to detect

the coupling signal of electron spin pairs on DNA duplex.

References: 1. Fazhan Shi, Qi Zhang, Boris Naydenov, Fedor Jelezko, Jiangfeng Du, Friedemann Reinhard, and Joerg Wrachtrup.

Quantum logic readout and cooling of a single dark electron spin, Phys. Rev. B, 87, 195414 (2013) 2. Fazhan Shi, Qi Zhang, Pengfei Wang, Hongbin Sun, Jiarong Wang, Xing Rong, Ming Chen, Chenyong Ju,

Friedemann Reinhard, Hongwei Chen, Joerg Wrachtrup, Junfeng Wang, and Jiangfeng Du. Single-protein spin resonance spectroscopy under ambient conditions, Science, 347, 1135 (2015)

3. Fazhan Shi, Xi Kong, Pengfei Wang, Fei Kong, Nan Zhao, Renbao Liu, and Jiangfeng Du. Sensing and atomic-scale structure analysis of single nuclear spin clusters in diamond, Nature Physics, 10, 21 (2014)

4. Tobias Staudacher, Fazhan Shi, S. Pezzagna, Jan Meijer, Jiangfeng Du, Carlos A. Meriles, Friedemann Reinhard, Joerg Wrachtrup. Nuclear magnetic resonance spectroscopy on a (5nm)

3 volume of liquid and solid samples,

Science, 339, 561 (2013)

Acknowledgements: This work is supported by NNSFC, MOST and CAS.

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79

Precise quantum control of spins in solids

Xing Rong, Jianpei Geng, Fazhan Shi, Jiangfeng Du

National Laboratory for Physics Sciences at the Microscale and Department of Modern Physics, University

of Science and Technology of China, Hefei, 230026, China.


Quantum computation provides great speedup over classical counterpart for certain problems,

such as quantum simulations, prime factoring and database searching. One of the challenges for

realizing quantum computation is to execute precise control of the quantum system in the presence

of noise. Recently, high fidelity control of spin-qubits has been achieved in several quantum

systems [1,2,3]. However, control of the spin-qubits with the accuracy required by the fault tolerant

quantum computation under ambient conditions remains exclusive. Here we demonstrate a

universal set of logic gates in nitrogen-vacancy centers with an average single-qubit gate fidelity of

0.99995 and two qubit gate fidelity of 0.992 [4]. These high control fidelities have been achieved in

the C naturally abundant diamonds at room temperature via composite pulses and optimal control

method. This experimental implementation of quantum gates with fault tolerant control fidelity sets

an important step towards the fault-tolerant quantum computation under ambient conditions.

References:

1. Jiangfeng Du*, Xing Rong, Nan Zhao, Ya Wang, Jiahui Yang, and R. B. Liu*, Preserving electron spin coherence in solids by optimal dynamical decoupling, Nature 461, 1265 (2009).

2. Ya Wang, Xing Rong, Pengbo Feng, Wanjie Xu, Bo Chong, Ji-Hu Su, Jiangbin Gong, and Jiangfeng Du*, Preservation of Bipartite Pseudoentanglement in Solids Using Dynamical Decoupling, Physical Review Letters 106, 040501 (2011).

3. Xing Rong, Jianpei Geng, Zixiang Wang, Qi Zhang, Chenyong Ju, Fazhan Shi, Chang-Kui Duan*, and Jiangfeng Du*, Implementation of dynamically corrected gates on a single electron spin in diamond, Physical Review Letters 112, 050503 (2014)

4. Xing Rong, Jianpei Geng, Fazhan Shi, Ying Liu, Kebiao Xu, Wenchao Ma, Fei Kong, Zhen Jiang, Yang Wu, and Jiangfeng Du*, Experimental fault-tolerant universal quantum gates with solid-state spins under ambient conditions, Nature Communications 6, 8748 (2015)

Acknowledgements: This work is supported by 973 Program (Grant No. 2013CB921800) and the NNSFC.

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80

Curious Electronic Phases and ESR Behaviors in One-Dimensional Organic

Conductors (TMTCF)2X

Mizue Asada1 and Toshikazu Nakamura

1,2

1Institute for Molecular Science, Okazaki 444-8585, Japan

2The Graduate University for Advanced Studies, Okazaki 444-8585, Japan


Organic conductors, (TMTCF)2X (C=S, Se) compounds are

the most well studied system as one-dimensional electronic

model system. They show various ground states, including spin-

Peierls, commensurate antiferromagnetic state (C-AF),

incommensurate spin density wave (IC-SDW), and

superconducting phases, realized by the substitution of X or

applying appropriate pressures. As a result, (TMTCF)2X shows

rich Pressue-Temperature electronic phase diagram.

(TMTTF)2Br undergoes antiferromagnetic transition at 16K

(TN). But it is located on the proximity between C-AF and IC-

SDW phase in the generalized phase diagram. Previously, we

examined the magnetic structure of the antiferromagnetic state

of (TMTTF)2Br by 1H-NMR spectroscopy at 4.2 K [1]. We

clarified that the wave-number of the antiferromagnetic state is

commensurate Q=(1/2, 1/4, 0) with amplitude 0.14μB/molecule

at 4.2K. The commensurate antiferromagnetic state of

(TMTTF)2Br was also confirmed by 13

C-NMR measurements

[2]. Recently Kawamoto and coworker found anomalous 13

C-

NMR spectra change in (TMTTF)2Br below 4.2 K. Hence we

also investigated antiferromagnetic resonance (AFMR) of

(TMTTF)2Br down to 1.5K using X-band ESR spectrometer.

Figure shows the angular dependence of AFMR modes (normal

mode and spin-flop mode) at 4.8K and 1.5K. The AFMR modes

seem to enhance at 1.5K, indicating development of the

magnetic moment of the AF sub-lattices [4] even at low-

temperatures (T << TN/2). Temperature dependence of the two

antiferromagnetic resonance (AFMR) modes also shows

anomalous increase below 5K. We also carried out 2D-NMR measurements for deuterated (d12-

TMTTF)2Br to investigate charge distribution by the quadrupole splitting at low temperatures.

Possible sub-phases in the antiferromagnetic state are discussed.

References: 1. T. Nakamura, T. Nobutoki, Y. Kobayashi, T. Takahashi and G. Saito, Synth. Met. 1995, 70, 1293. 2. (a) E. Barthel, G. Quirion, P. Wzietek, D. Jérome, J. B. Christensen, M. Jørgensen and K. Bechgaard, Europhys. Lett.

1993, 21, 87, (b) S. Hirose, Y. Liu and A. Kawamoto, Phys. Rev B 2013, 88, 125121. 3. T. Ihachi et al., JPS Spring meeting 2015, 21aAs-2. 4. H. Ohta, N. Yamauchi, T. Nanba, M. Motokawa, S. Kawamata and K. Okuda, J. Phys. Soc. Jpn. 1993, 62, 785.

(Top) Angular dependence of the

antiferromagnetic resonance in

(TMTTF)2Br (easy-intermediate plane:

X-band) .

(Bottom) Temperature dependence of

AFMR modes (normal and spin-flop)0.

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81

Light-induced Generation of Entangled Nuclear Spin Qubits

in Molecular Crystals

Gerd Kothe,1 Michail Lukaschek,

1 Tomoaki Yago,

2 Gerhard Link,

1

Konstantin L. Ivanov3,4

and Tien-Sung Lin5

1Department of Physical Chemistry, University of Freiburg, Freiburg 79104, Germany

2Department of Chemistry, Saitama University, Saitama 338-8570, Japan

3International Tomography Centre of SB RAS, Novosibirsk 630090, Russia

4Novosibirsk State University, Novosibirsk 630090, Russia

5Department of Chemistry, Washington University, St. Louis MO 63130, USA


In 1935, Schrödinger coined the term “entanglement” to denote a peculiar quantum interaction

in which the properties of two or more physical objects can be correlated, even when they are

separated. Since then, entanglement has been proven for a number of different physical solids such

as quantum dots, ion traps, superconductors and optically polarized defect centres in diamond and

silicon carbide. In this contribution, we should like to introduce specific molecular solids as

versatile quantum systems in which questions related to entanglement can be explored. The story

begins about 40 years ago when huge nuclear spin polarization has been detected in organic triplet

states at level anti-crossing (LAC) conditions [1-3]. So far, however, the quantum interaction

responsible for the nuclear hyperpolarization was not identified. Here, we explore this interaction

on the basis of an analytical theory using pulsed low-field magnetic resonance in combination with

pulsed laser excitation. Model system is triplet pentacene in a host single crystal.

Study reveals that a laser pulse generates the triplet state and initiates entanglement between an

electron spin and 14 hyperfine coupled proton spins. This gives rise to huge oscillatory electron and

nuclear spin polarization. Then, by the action of a resonant high-power microwave pulse, the

electron spin is disentangled from the nuclear spins. As a result, the longitudinal electron and

nuclear spin magnetization evolve separately. Due to multipartite entanglement of 14 proton spins,

one observes quantum oscillations [4] in the nuclear spin polarization in the form of frequency

combs. Thus, at triplet LAC conditions, a vast number of entangled nuclear spin qubits is created

simply by a laser pulse. The total of spin qubits induced depends on the type and number of

hyperfine coupled nuclei which can be tailored by chemical synthesis. Because of the huge

polarization, generated at LAC, these quantum systems are capable of forming genuine multipartite

entanglement at ambient conditions. This makes them promising candidates for various applications

in quantum information processing.

References:

1. W.S. Veeman, A.L.J. van der Poel, J. H. van der Waals, Mol. Phys. 1975, 29, 225-248. 2. V.A. Atsarkin, S.K. Morshnev, Sov. Phys. JETP 1976, 44, 795-800. 3. J.P. Colpa, D. Stehlik, Chem. Phys. 1977, 21, 273-288. 4. G. Kothe, T. Yago, J.-U. Weidner, G. Link, M. Lukaschek, T.-S. Lin, J. Phys. Chem. B 2010, 114, 14755-14762.

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82

Mobility and Reactivity of 4-Substituted TEMPO Derivatives in Metal-Organic

Framework MIL-53(Al)

Artem Poryvaev,1,2

Alena Sheveleva,1,2

Daniil Kolokolov,2,3

Alexander Stepanov,2,3

Matvey Fedin,1,2

Elena Bagryanskaya2,4

1International Tomography Center SB RAS, Institutskaya 3a, 630090, Novosibirsk, Russia

2Novosibirsk State University, Pirogova 2, 630090, Novosibirsk, Russia

3Boreskov Institute of Catalysis SB RAS, Lavrentiev av. 5, 630090, Novosibirsk, Russia

4N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Lavrentiev av. 9, 630090, Novosibirsk,

Russia


Post-synthetic adsorption of stable nitroxide radical probes in diamagnetic nano/mesoporous

metal-organic frameworks (MOFs) allows application of Electron Paramagnetic Resonance (EPR)

for studying structure, functions and corresponding guest-host interactions in such MOFs. This

approach was recently demonstrated using (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)

embedded in structurally-flexible MIL-53(Al), with the mobility and reactivity of TEMPO

reflecting structural dynamics of MOF [1]. In the present work we embed three derivatives of

TEMPO (4-oxo-TEMPO, 4-hydroxo-TEMPO, 4-acetamido-TEMPO) in MIL-53(Al) and

investigate structural “breathing” of this MOF with temperature in order to gain deeper

understanding of underlying guest-host interactions. Different substituents in piperidine ring lead to

different mobility and reactivity of corresponding nitroxides. The obtained EPR data and Molecular

Dynamics (MD) calculations show that the

efficiency of nitroxide radical reaction with μ2-

hydroxo group of MIL-53(Al) strongly correlates

with the character of its molecular motion, and the

reversibility of this reaction upon structural

“breathing” is a general phenomenon. Based on

these findings, practical suggestions on selecting

spin probes for in-MOF EPR studies are formulated.

References:

1. Sheveleva A.M., Kolokolov D.I.,

Gabrienko A.A., Stepanov A.G., Gromilov S.A., Shundrina I.K., Sagdeev R.Z., Fedin M.V., Bagryanskaya E. G., J. Phys. Chem. Lett. 2014, pp 20−24.

Acknowledgements

This work was supported by the Russian Science Foundation (No. 14-13-00826). Theoretical MD study was

supported by the Russian Foundation for Basic Research (No. 14-03-00224) and the RF President’s Grant (MD-

276.2014.3). Investigation of reactivity of nitroxides was supported by FASO Russia (project 0333-2014-0001).

OR-30


83

Proton matrix ENDOR study on the structure of Ca2+-

depleted and NH3-binding

Mn cluster in photosystem II

Hiroki Nagashima and Hiroyuki Mino

Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku,

Nagoya, Aichi, 464-8602, Japan


Photosynthetic oxygen evolution is one of the key reactions for oxygenic life on the earth,

performed in Mn cluster in photosystem II protein complex. Recent X-ray crystal structure [1, 2]

revealed that Mn cluster consists of four Mn, five O and one Ca. Four water molecules are ligated

to the Mn ion and the Ca ion (W1 – W4). The Mn cluster has five different redox states, called Sn-

state (n = 0 - 4). After photo induced charge separation on the reaction center of photosystem II,

Mn cluster is oxidized via tyrosine residue YZ and S-state is advanced to the next state (Sn to Sn+1).

During each transition of S-states, one or two protons are released to out of photosystem II. The

unstable intermediate state, S4, is reduced to the S0 state immediately with production of molecular

oxygen. However, X-ray crystal structure revealed only the stable S1 state and protons are not

identified. The mechanisms of O-O bond formation and proton release are still unclear.

In order to detect protons, we applied ENDOR technique to S2 state Mn cluster. ENDOR is

powerful method to detect hyperfine interactions between protons and Mn cluster. Seven pairs of

ENDOR peaks were detected. Fig. 1 shows the structure model of S2 state Mn cluster based on

crystal structures. ENDOR signals were assigned to the protons of water molecules W1-W4 ligated

to Mn and Ca ions. Ca2+

-depleted, NH3-treated D2O-treated samples were examined in order to

perturb the structure of the Mn cluster. ENDOR results showed that (1) Ca2+

-depletion disrupts

hydrogen-bond network near the Mn cluster that has significant roles for proton release [3] and

electron transfer, (2) NH3 is replaced with W1 ligated to Mn ion and interacts to the hydrogen-bond

network surrounding Mn cluster, (3) W2 has slow exchange rate and is OH- in the S1 and S2 state.

The exchange rate is significantly slow relative to the substrate water molecules [4]. Additionally,

NH3 does not modify the oxygen-evolving activity and the NH3 binding site is not substrate water

site [4]. We concluded that both W1 and W2 are excluded from candidates of substrate water. We

suggest that substrate water sites are O5 site and the closest water, W3.

References: 1. Y. Umena et al., Nature, 2011, 473, 55-60. 2. M. Suga et al., Nature, 2015, 517, 99-103 3. S. Nakamura et al., Biochemistry, 2014, 53, 3131-3144. 4. Navarro et al., PNAS, 2013, 110, 15561-15566

Acknowledgements

This work is supported by a Program for Leading Graduate Schools

“Integrative Graduate Education and Research in Green Natural

Sciences,” MEXT (Ministry of Education, Culture, Sports, Science and

Technology), Japan; Grant-in-Aid for JSPS (Japan Society for the

Promotion of Science) Fellows 26011113 (to H. N.); and MEXT/JSPS

Grant-in-Aid for Exploratory Research 26620003 (to H. M.).

Fig.1. Structure model based on

ENDOR and crystal structure [1].

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84

PELDOR study on the high-affinity Mn2+

site of the photoactivation of the

oxygen-evolving complex in photosystem II

Mizue Asada,1,2

Hiroyuki Mino2

1Institute for Molecular Science, Okazaki 444-8585, Japan

2Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan


Photosynthetic water oxidation is carried out by Photosystem (PS) II protein complex. The

water molecules are directly oxidized by oxygen-evolving complex (OEC), which consists of four

Mn, one Ca, five O ions and surrounding amino acids. Formation process of OEC is called as

'photoactivation', starting with incorporation of one Mn2+

ion on to the apo-OEC-PS II [1]. The

Mn2+

ion is oxidized to Mn3+

by illumination, then another Mn2+

ion binds to PS II through the

structural rearrangement, and the next intermediate state is formed. Further illumination and

binding of additional Mn2+

and Ca2+

ions accomplish the photoactivation, and PS II earns the

oxygen evolving activity. There is one specific high-affinity Mn2+

site in the initial step of the

photoactivation. Site-directed mutagenesis studies have been investigated to detect the high-affinity

Mn2+

site [2, 3], however, there is still no direct evidence about the exact location of Mn2+

binding

site.

In this study, the location of the high-affinity Mn2+

site in apo-OEC-PS II was investigated by

pulsed electron-electron double resonance (PELDOR). MnCl2 was mixed with OEC-depleted PS II

membranes and then the samples were concentrated. We measured the dipole interaction between a

stable tyrosine radical YD• and the Mn

2+ binding site in the oriented PS II membranes. The distance

between YD• and the high-affinity Mn

2+ site was estimated to be 30.5 Å assuming the point-dipole

approximation. The narrow distance distribution of the PELDOR signals indicate that the Mn2+

binding site is located in the immobile site. The anisotropy of PELDOR signals was detected at the

angle between the membrane normal and the extrinsic magnetic field is parallel and perpendicular.

The PELDOR oscillations calculated using the molecular structure of PS II from the

crystallography provided the possible area of the high-affinity Mn2+

site [4]. Assuming the Mn2+

binding site is in the OEC, the Mn2+

locates at the position of Mn4. As the position of Mn4 is

surrounded by Glu333 and Asp170, binding of Mn2+

ion to the high-affinity site might determine

the orientation of the two carboxylates in the first step of photoactivation.

References:

1. D. J. Vinyard, G. M. Ananyev and G. C. Dismukes, Annu. Rev. Biochem., 2013, 82, 577-606 2. P. J. Nixon and B. A. Diner, Biochemistry, 1992, 31, 942-948 3. K. A. Campbell, D. A. Force, P. J. Nixon, F. Dole, B. A. Diner, R. D. Britt, J. Am. Chem. Soc., 2000, 122, 3754-3761 4. M. Suga, F. Akita, K. Hirata, G. Ueno, H. Murakami, Y. Nakajima, T. Shimizu, K. Yamashita, M. Yamamoto, H.

Ago and J-R. Shen, Nature, 2014, 517, 99-103

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85

Saccharides as Prospective Immobilizers of Nucleic Acids for Room-

Temperature Structural EPR Studies

Andrei Kuzhelev,1,4

Georgiy Shevelev,2,4

Olesya Krumkacheva,3,4

Victor Tormyshev,1,4

Dmitrii

Pyshnyi,2,4

Matvey Fedin,3,4


1N.N. Voroztsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9,

Novosibirsk, 630090, Russia 2Institute of Chemical Biology and Fundamental Medicine SB RAS, Pr. Lavrentjeva 8,

Novosibirsk, 630090, Russia 3International Tomography Center SB RAS. Institutskaya ЗА, Novosibirsk, 630090, Russia

4Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia


Pulsed Dipolar Electron Paramagnetic Resonance (EPR) spectroscopy is a powerful tool for

structural studies of biomolecules and their complexes. This method, whose applicability has been

recently extended to physiological temperatures, requires immobilization of studied biosystem to

prevent averaging of dipolar couplings; at the same time, the modification of native conformations

by immobilization must be avoided. Disaccharide trehalose perfectly fulfils both purposes for

proteins; however its applicability for nucleic acids was questionable and not investigated so far. In

this work we provide first demonstration of room-temperature EPR distance measurements on

model spin-labeled DNA duplexes immobilized in trehalose, sucrose and glucose.

We have analyzed different ways of sample dehydration and have discovered a reliable

approach that keeps structural conformation and unity of the complex. The obtained spin-spin

distances in all three saccharides agree well with our previous data using anionic-exchange sorbent

[1]; however among glucose, sucrose and trehalose the latter gives the best accuracy. Finally, room-

temperature electron spin dephasing time of triarylmethyl label in trehalose is noticeably longer

compared to glucose, sucrose and other immobilizers used previously, thus providing a longer range

of available distances. Therefore, saccharides, and especially trehalose, can be efficiently used as

easy-to-handle immobilizers of nucleic acids and their complexes, mimicking native conditions and

allowing broad range of structural EPR studies at room temperatures [2].

References:

1. G. Y. Shevelev, O. A. Krumkacheva, A. A. Lomzov, A. A. Kuzhelev, O. Yu. Rogozhnikova, D. V. Trukhin, T. I. Troitskaya, V. M. Tormyshev, M. V. Fedin, D. V. Pyshnyi, E. G. Bagryanskaya, J. Am. Chem. Soc. 2014, 136, 9874-9877.

2. A. A. Kuzhelev, G. Y. Shevelev, O. A. Krumkacheva, V. M. Tormyshev, D. V. Pyshnyi, M. V. Fedin, E. G. Bagryanskaya, J. Phys. Chem. Lett. 2016, 7, 2544−2548

Acknowledgements:

This work was supported by Russian Science Foundation (no. 14-14-00922).

OR-33



86

ESEEM Study of Molecular Motions of Deuterated Molecules

nearby the Spin Label

Victoria Syryamina,1,2

Alexander Maryasov,1 Michael Bowman,

3 Sergey Dzuba

1,2

1Voevodsky Institute of Chemical Kinetics and Combustion, Institutskay Str.3, Novosibirsk, 630090, Russia

2Novosibirsk State University, Pirogova Str. 2, Novosibirsk, 630090, Russia

3The University of Alabama, Department of Chemistry, Tuscaloosa, AL 35487, USA

[email protected]

The Electron Spin Echo Envelope Modulation (ESEEM) spectroscopy is a powerful tool for

studying weak electron-nuclear hyperfine interactions (HFI) and nuclear quadrupole interactions

(NQI). The ESEEM amplitude for remote nuclei decreases with distances r from the nuclei as r-6

, so

it is sensitive only to the nearest surrounding of the spin label. For deuterium nuclei the

characteristic distance for observation of narrow ESEEM line centred at the deuterium Larmor

frequency at EPR X-band is r ~ 0.5 nm. To separate HFI and NQI in ESEEM spectra, the

combination of microwave three- and four-pulse sequences may be applied.

Both HFI and NQR are sensitive to molecular motions, which is demonstrated for the test

system of nitroxide with deuterated methyl groups in glassy o-terphenyl matrix.1 In the four-pulse

experiment, a well-resolved Pake-pattern splitting of the narrow ESEEM line was observed below

100 K, this splitting disappears with temperature increase. ESEEM lineshape analysis allows to

observe the onset of molecular motions with correlation time of τc~10-6

s. The found Arrhenius

parameters of the methyl groups rotation are in agreement with the literature data. ESEEM data for

experiment for deuterated o-terphenyl matrix indicate on librations of the host o-terphenyl

molecules.

In experiments with spin label in glassy mixtures of deuterated water and DMSO, fast restricted

motions of water molecules around label was found near the glass transition temperature, Tg. In

CW EPR noticeable changes are observed only at temperatures above ~ 1.5Tg.

In experiments with spin-labeled model biological membranes hydrated by deuterated water,

the transition from restricted to unrestricted motions of water molecules was observed between 160

and 180 K. The temperature of this transition was found to depend on the membrane lipid

composition – the fully saturated membrane “retards” from unsaturated membrane by 15-20 K, that

correlates with the phenomenon of dynamical transition in the membrane interior observed by

Raman and EPR spectroscopies.2

References: 1. Syryamina et al. J Magn. Reson. 2016, 261,169. 2. Surovtsev et al. J. Phys. Chem. B, 2012, 116, 8139.

Acknowledgements

This work was supported by the Russian Science Foundation, project # 15-15-00021

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87

Electronic Structure and Properties of New Nitronyl and Imino Nitroxide

Diradicals: DFT and ab initio Study

Dmitry E. Gorbunov,1,2

Evgeny V. Tretyakov,3 Nina P. Gritsan

1,2

1Novosibirsk State University, Pirogova Street, 2, 630090 Novosibirsk, Russian Federation

2Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, 3 ul. Institutskaya,

630090 Novosibirsk, Russian Federation 3Vorozhtsov Institute of Organic Chemistry, Russian Academy of Sciences, Ak. Lavrentiev Avenue 9, 630090

Novosibirsk, Russian Federation


In recent years, organic diradicals have received a new impetus in the fields of fundamental

chemistry and materials science. Organic diradicals with the singlet ground state are in the spotlight

as candidates for (opto)electronic devices and as building blocks for multifunctional responsive and

spin injection/transporting materials for spintronic devices.1,2

There is still a growing interest in the

diradicals with the triplet ground state and their complexes with transition metals which are the

building blocks of molecular magnetic materials.3,4

Understanding the electronic structure and magnetic properties of diradicals and their

complexes requires application of both a set of experimental techniques and quantum chemical

calculations. The report will present and discuss the results of calculations for a large series of

nitronyl nitroxide (1, 3, 5) and iminonitroxide (2, 4, 6) diradicals and their Cu(II) complexes in

comparison with the results of the EPR and magnetic susceptibility () measurements for

polycrystalline samples in a wide temperature range.

Diradicals under study belong to both the disjoint (e.g. TMM type) or non-disjoint (e.g. PMP

type) non-Kekule structures. It was demonstrated that DFT calculations predict well parameters of

the EPR spectra (ZFS and hfc constants), thus correctly reproducing spin-density distribution.

However, to predict singlet-triplet energy splitting for diradicals with disjoint SOMOs, high-level

calculations (e.g. CASSF/NEVPT2) are required. Fortunately, to calculate intermolecular exchange

interactions or exchange interactions between paramagnetic centers of the metal complexes, the

diradicals of the latter type could be divided into two radical fragments. Calculated parameters of

the intra- and intermolecular exchange interactions were used to choose magnetic motifs and to

analyze (T) dependences of the diradicals and complexes under study.

References:

1. A. Iwasaki, L. Hu, R. Suizi et al., Angew. Chem. Int. Ed. 2009, 48, 4022. 2. Z. Sun, Z. Zeng, J. Wu, Acc. Chem. Res. 2014, 47, 2582. 3. E.V. Tretyakov, S.E. Tolstikov, G.V. Romanenko, A.S. Bogomyakov, D.V. Stass, A.G. Maryasov, N.P. Gritsan, V.I.

Ovcharenko, Russ. Chem. Bull. 2011, 60, 2608. 4. S. Tolstikov, E. Tretyakov, S. Fokin, E. Suturina, G. Romanenko, A. Bogomyakov, D. Stass, A. Maryasov, N.

Gritsan, V. Ovcharenko., Chem. Eur. J., 2014, 20, 2793.

Acknowledgements:

This work was supported by the Russian Science Foundation (project 16-13-10155).

OR-35


88

Microstructuring of ionic liquids studied by time-resolved EPR of photoexcited

triplets

Mikhail Ivanov,1,2

Sergey Veber,1,2

Sergey Prikhod’ko,3 Nikolay Adonin,

3

Elena Bagryanskaya,1,2,4

Matvey Fedin1,2

1 Novosibirsk State University, 2 Pirogova Str., Novosibirsk, 630090, Russia

2 International Tomography Center, 3A Institutskaya Str., Novosibirsk, 630090, Russia

3 Boreskov Institute of Catalysis SB RAS, 5 Ac. Lavrentieva ave., Novosibirsk, 630090, Russia

4 N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, SB RAS, 9 Ac. Lavrentieva ave.,

Novosibirsk, 630090, Russia


Unusual physical properties of ionic liquids (ILs) can be implemented in many different

applications and are very sensitive to the structure of IL. In current work, we investigate the

influence of microviscosity and nanostructuring of ILs on spin dynamics of the dissolved

photoexcited molecules. Three ILs [Bmim]PF6, [Bmim]BF4 and [C10mim]BF4 were used as

solvents and photoexcited Zn tetraphenylporphyrin (ZnTPP) as a probe. In this work time-resolved

EPR (TR EPR) of photoexcited triplets was applied to probe microstructuring in ILs at low

temperature region (100-270 K). TR EPR data clearly indicate the presence of two

microenvironments of ZnTPP in frozen ILs at 100−200 K, being manifested in different spectral

shapes and different spin relaxation rates. We assign observed heterogeneities to micelle-like

cavities with ZnTPP localized inside. The formation of heterogeneities upon freezing of ILs was

confirmed by additional experiments using continuous wave EPR and stable nitroxide as a probe.

Thus, TR EPR of photoexcited triplets can be effectively used for probing heterogeneities and

nanostructuring in frozen ILs. In addition, the increase of polarization lifetime in frozen ILs is an

interesting finding that might allow investigation of short-lived intermediates inaccessible

otherwise.

Acknowledgements:


OR-36




89

Continuous Wave and Time-Resolved EPR Study of Photoinduced Radicals in

Fluoroacrylic Porous Polymer Films

A.M. Sheveleva,1,2

M.Yu. Ivanov,1,2

S.L. Veber,1,2

I.K. Shundrina,3 V.V. Shelkovnikov,

3

E.G. Bagryanskaya, 2,3

M.V. Fedin1,2



3N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Lavrentiev av. 9, 630090, Novosibirsk,

Russia


Fluoroacrylic polymers with inherent micro/nanoporosity are promising media for

incorporation of fluorescent molecules and following application as pressure sensitive paints

(PSPs), and UV photostability of PSPs is critically important for their long-term performance.

Although photodegradation mechanisms of fluoroacrylic polymers have been studied previously in

solutions, they have never been addressed in practically-relevant for PSPs solid state porous films.

In this work we combined Continuous Wave (CW) and Time-Resolved (TR) Electron Paramagnetic

Resonance (EPR) to study UV photodegradataion of thin porous films of a few representative

fluoroacrylic polymers. Different types of spectra were detected using CW and TR EPR and

assigned to the species formed on the inner surface of the pores and in the bulk of the polymer,

respectively. The radical pairs formed in the bulk are short-lived, as is evidenced by TR EPR, and

most likely recombine back to the initial polymer. On the contrary, the radicals formed on the

surface of pores are metastable in the absence of oxygen; they can be studied by CW EPR and

clearly assigned to the radicals of type C(CH3)CH2- (so-called propagating radicals) formed via the

cleavage of C-C bond of the ester side chains and consecutive -scission. Remarkably, their CW

EPR spectra closely resemble solution-state spectra, indicating that these radicals are localized in

the pores where the mobility of methyl and methylene protons is not suppressed. Thus, based on

complementary results of CW and TR EPR, we conclude that UV photodegradation of porous

fluoroacrylic polymer films mainly occurs on the inner surface of the pores, which needs to be

considered in future development of this type PSPs.

Acknowledgements

We are grateful to the the Russian Science Foundation (no. 14-13-00826) for financial support.

OR-37


90

Light-Induced Charge Transfer State in P3HT/PC70BM Composite as Studied

by Out-of-Phase Electron Spin Echo Spectroscopy

E.A. Lukina,1,2

A.A. Popov1,2

and L.V. Kulik1,2

1Voevodsky Institute of Chemical Kinetics and Combustion of Siberian Branch of Russian Academy of

Sciences, Institutskaya 3, Novosibirsk 630090, Russia 2Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russia


Organic photovoltaics (OPV) is a rapidly developing field, but despite the significant progress

in power conversion efficiency, the mechanism of light-induced charge separation is still unclear.

During charge separation process the intermediate state called charge transfer (CT) state is formed.

Due to low dielectric constant of organic materials the coulomb attraction in CT state is much

higher than room temperature thermal energy. The mechanism helping CT state to separate into free

charges still remains the challenge. To solve this problem the knowledge of structure and properties

of charge-transfer state is required.

We studied a light-induced CT state in composite of conductive polymer P3HT and fullerene

derivative PC70BM by out-of-phase electron spin echo, known to be a powerful tool for spin-

correlated radical pairs studies [1]. Recently this method was applied to another benchmark

composite P3HT/PC60BM [2]. The out-of-phase ESE signal was observed under the laser pulse

irradiation of the composite at low temperature. We assume that during charge separation process

initially the spin-correlated radical pairs in singlet-polarized spin state are formed and after the spin

evolution the emission/absorption (E/A) polarized radical pairs appear. Both types of polarizations

contribute to the out-of-phase ESE signal. Analytical calculation of echo shape for both types of

initial polarization revealed that contribution of E/A-polarized radical pairs becomes zero after

averaging over the whole EPR spectrum of the system. This behavior was confirmed

experimentally; thus the analysis of out-of-phase ESE signal was simplified. Interspin distance

distributions in the charge transfer state were obtained from modeling of out-of-phase ESEEM

measured at 65K at different delays after laser flash TDAF=300 ns; 1.3μs and 3.3μs. The dipolar

interaction parameters were determined by quantum chemical calculation, thus charge

delocalization over P3HT chain was taken into account. We assumed a simple distance distribution

consisting of two halves of Gaussian functions with common center and different width. The

average distance between charges increases with TDAF increase; also the distribution becomes

significantly broader with larger distances prevailing at longer TDAF values. Such behavior is

presumably caused by two simultaneous processes: diffusion of the radicals from the interface and

geminate recombination of radical pairs with small distances between radicals.

References:

1. A.J. Hoff, P. Gast, S.A. Dzuba, C.R. Timmel, C.E. Fursman, P.J. Hore. Spectrochim. Acta, Part A 1998, 54, 2283-2293.

2. E.A. Lukina, A.A. Popov, M.N. Uvarov, L.V. Kulik. J. Phys. Chem. B, 2015, 119, 13543-13548.

Acknowledgements:

The work was supported by the Russian Foundation for Fundamental Research grant № 15-03-07682a, by the Ministry

of Science and Education of Russian Federation, and by Alexander von Humboldt Foundation research group linkage

project "Light-induced processes and paramagnetic species in organic photovoltaics and photosynthesis".

OR-38


91


Egor A. Nasibulov,1,2 Alexey S. Kiryutin,1,2 Alexandra V. Yurkovskaya,1,2

Hans-Martin Vieth1,3 and Konstantin L. Ivanov1,2

1International Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3A, Novosibirsk, 630090, Russia

2Novosibirsk State University, Pirogova str. 2, Novosibirsk, 630090, Russia 3Freie Universität Berlin, Arnimallee 14, Berlin, 14195, Germany


DNP is a powerful method to create non-thermal polarization of nuclear spins, thereby

enhancing their NMR signals. The DNP effect is due to transfer of the electron spin polarization to nuclear spins in the presence of MW-pumping; the NMR enhancement is proportional to the ratio of the magnetogyric ratios of electron 훾 and nucleus 훾 . In the case of Overhauser-type DNP (DNP in liquids) the NMR signal enhancement is

휀 = 1 + 휉 ⋅ 푓 ⋅ 푠 ⋅훾훾 (1)

with 휉, 푓 and 푠 being the coupling factor, leakage factor and saturation factor, respectively. It is well-known that MW-pumping, required for reaching maximal 푠 values, can cause substantial heating of the sample. For this reason, using pulsed techniques of pumping instead of cw-pumping is of great interest [1].

Here Overhauser-type DNP formed by a periodic sequence of EPR-pulses is discussed. Earlier [2] the case of a single ideal pulse per period was discussed and an elegant general expression for the NMR enhancement has been obtained. The expression for the enhancement was shown to be similar to that known for cw-pumping with the saturation factor re-defined as the deviation of the electron spin magnetization from its equilibrium value averaged over the cycle of the pulse sequence.

In this work a general theoretical approach to pulsed Overhauser-type DNP is presented. Our theory can treat pulsed irradiation of EPR transitions for an arbitrary periodic pulse sequence. The NMR enhancement is analyzed in detail as a function of the EPR-pulse length for ideal pulses and pulses with a finite rise-time. It is shown that one can achieve the maximal theoretically allowed NMR enhancement for pulsed pumping even when the duty cycle of pumping is low. Characteristic oscillations of the DNP enhancement are found when the pulse length is stepwise increased, originating from the coherent motion of the electron spins driven by the pulses. The dependence of the DNP effect on the duty cycle, pulse length and electron spin relaxation times has been studied in detail. Once the lines in the EPR spectrum are inhomogeneously broadened, higher DNP effects are expected in the pulsed pumping mode than in the cw-mode for the same total power of microwave irradiation. Experimental low-field DNP data are in good agreement with this theoretical approach. References: 1. M. Alecci, D.J. Lurie, J. Magn. Reson. 1999, 138, 313-319. 2. E.A. Nasibulov, K.L. Ivanov, A.V. Yurkovskaya and H.-M. Vieth, Phys. Chem. Chem. Phys., 2012, 14, 6459-6468. Acknowledgements: This work has been supported by the Russian Foundation for Basic Research (projects No. 16-33-00590, 14-03-00397).

OR-39


91-B

Characterization of Mn2+ doped PbS nanocrystals using various techniques

Ram Kripal, Upendra M. Tripathi

EPR Laboratory, Department of Physics, University of Allahabad, Allahabad – 211002, India

Email: [email protected], [email protected]

Mn2+ doped PbS semiconductor nanocrystals are synthesized by simple chemical route.

Variation of the shape and size of PbS from bulk material to nanocrystal structures changes the band gap energy from 0.39 eV to 5.2 eV1-2. The Mn: PbS nanocrystals have cubic structure (space group: Fm3m)3-4. The average crystallite size of nanocrystals lies between 5 nm to 10 nm as obtained by X-ray diffraction (XRD) study. The Mn: PbS nanocrystals are also characterized by UV/VIS optical absorption, Photoluminescence (PL) and Transmission electron microscopy (TEM). The magnetic properties of Mn: PbS nanocrystals are studied using Electron paramagnetic resonance (EPR)5-8. The EPR shows the existence of Mn2+ in PbS nanocrystals9. The spectroscopic splitting factor of the sample g, the hyperfine splitting constant A and the crystal field strength D are obtained as 1.9984, 87.579×10-4 cm-1, 83.25×10-4 cm-1 respectively.

Keywords: Nanocrystals, XRD, TEM, EPR. References: 1. D. Kumar, G. Agarwal, B. Tripathi, D. Vyas, V. Kulshrestha, J. of Alloys and Comp., 484 (2009) 463-466. 2. L.F. Koao, F. B. Dejeneand H.C. Swart, Synthesis of PbS Nanostructures by Chemical Bath Deposition Method, Int.

J. Electrochem. Sci., 9 (2014) 1747 – 1757. 3. S. I. Sadovnikov, N. S. Kozhevnikova, V. G. Pushin, and A. A. Rempel, Microstructure of Nanocrystalline PbS

Powders and Films, Inorganic Materials, 48(1) (2012) 21 - 27. 4. N. S. Belova and A. A. Rempel, PbS Nanoparticles: Synthesis and Size Determination by X-ray Diffraction,

Inorganic Materials, 40(1) (2004) 3 - 10. 5. Atul K. Gupta and Ram Kripal, EPR and photoluminescence properties of Mn2+ doped CdS nanoparticles

synthesized via co-precipitation method, Spectrochemica Acta A(96) (2012) 626 - 631. 6. Huijuan Zhou, Detlev M. Hofmann, Helder R. Alves, and Bruno K. Meyer, Correlation of Mn local structure and

photoluminescence from CdS: Mn nanoparticles J. Appl. Phys., 99 (2006) 103502(4 pages). 7. P. H. Borse, D. Srinivas, R. F. Sinde, S. K. Date, W. Vogel, and S. K. Kulkarni, Effect of Mn2+ concentration in ZnS

nanoparticles on photoluminescence and electron-spin- resonance spectra Phys. Rev. B, 60 (1999) 8659 - 8664. 8. R. Kripal and A. K. Yadav, EPR and Optical Absorption Study of Fe3+ Doped Monohydrated Dipotassium Stannic

Chloride, Appl. Magn. Reson. 46 (2015) 323-335. 9. Atul K. Gupta, Ram Kripal, EPR and photoluminescence properties of Mn2+ doped CdS nanoparticles synthesized via

co-precipitation method, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 96 (2012) 626–631.

Acknowledgements: The authors are very grateful to the Head, Department of Physics for providing departmental facilities, Asso. Prof. Suneet Dwivedi, Dr. Manvendra Kumar and Dr. Vikas Barnwal, Nanophosphor Application Center University of Allahabad, Allahabad, India, for providing XRD facility and SAIF IIT Bombay for giving EPR and TEM facilities. The author Upendra M. Tripathi is also thankful to U.G.C. for providing Junior Research Fellowship.

OR-39B


92

EPR and Magnetic Studies of Bi0.5Sr0.5Mn0.9Cr0.1O3

K.S. Bhagyashree,1 R. Damle

2 and S.V. Bhat

1

1Department of Physics, Indian Institute of Science, Bangalore-560012, India

2Department of Physics, Bangalore University, Bangalore-560056, India


Due to the presence of the highly polarizable 6s2 lone pair electrons on the Bi

3+ ion. Bi based

manganites such as Bi0.5Sr0.5MnO3 exhibit robust charge ordering (TCO ∼ 525 K) and

antiferromagnetism (TN ∼ 110 K) [1]. It has been shown that in Bi0.5Sr0.5MnO3 nanoparticles both

CO and AFM phases remain unaffected unlike in other doped rare-earth manganites [2]. In this

work we explore the efficacy of another method of suppressing the CO, namely doping ‘Cr’ at ‘Mn’

sites [3]. Polycrystalline bulk Bi0.5Sr0.5Mn0.9Cr0.1O3 sample was prepared by the conventional solid

state method and characterized by powder XRD and Electron Probe Micro Analysis (EPMA).

Magnetization measurement done using a PPMS instrument in the temperature range 5 – 400 K

showed that the sample undergoes a ferromagnetic (FM) transition at ~ 50 K, above which the

sample is in the paramagnetic phase till 400 K. X-band EPR signals down to 70 K could be fitted to

broad Lorentzian line shapes and the EPR parameters were extracted. A few typical EPR signals at

different temperatures are presented in Fig.1. Main panel of Fig.2 shows the temperature

dependence of 1/Intensity vs. temperature according to which the sample undergoes an FM

transition at ~ 80 K while according to the susceptibility data (presented in the inset to Fig.2) the

FM transition is at ~ 50 K. This difference most probably arises from the fact that EPR, being a

dynamic technique, is sensitive to the fluctuating ferromagnetic cluster formation. Fig.3 shows the

plot of linewidth vs temperature. The data are fitted to the empirical relation log (∆H-∆H (∞)) vs.

log (T-TC), based on Huber and Seehra’s work [4,5], in order to understand the linewidth broadening

near the transition temperature (presented in the inset to Fig.3).

References:

1. M. Hervieu, A. Maignan, C. Martin, N. Nguyen, and B. Raveau, Chemistry of Materials, 2001, 13,1356 2. S. S. Rao and S. V. Bhat, Journal of Nanoscience and Nanotechnology, 2007, 7, 2025 3. C. M. Xiong, J. R. Sun, R. W. Li, S. Y. Zhang, T. Y. Zhao, and B. G. Shen, Journal of Applied Physics, 2004, 95,

1336 4. Mohindar S. Seehra and T.G. Castner Jr. Solid State Communications, 1970, 8(10), 787-790 5. D. L. Huber. Phys. Rev. B, 1972, 6, 3180-3186

50 100 150 200 250 300

6.0x10-14

8.0x10-14

1.0x10-13

1.2x10-13

1.4x10-13

1.6x10-13

I-1(a

rb.u

nit

s)

T(K)

0 50 100 150 200 250 300 350 400

0.000

0.002

0.004

0.006

(e

mu

/g.O

e)

T(K)

0.0 2.0k 4.0k 6.0k 8.0k 10.0k

50K

100K

Fit

160K

Fit

210K

Fit

dP

/dH

(arb

.un

its

)

H(G)

300K

Fit

50 100 150 200 250 300

3000

3500

4000

4500

5000

5500

1.4 1.6 1.8 2.02.6

2.7

2.8

2.9

3.0

log

(H

-H

())

log(T-Tc)

Fit to the power law

H

pp(G

)

T(K)

Fig.1: Typical EPR signals

at different temperatures

Fig.2: Temperature

dependence of inverse

intensity; inset shows

temperature dependence of

susceptibility

Fig.3: Temperature

dependence of peak to peak

linewidth; inset shows the fit

to the Huber-Seehra empirical

relation

OR-40


93

CW Time-Resolved and pulse EPR investigations of photoinduced spin states of

metalloporphyrin derivatives systems

Andrey Sukhanov,1 Violeta Voronkova,

1 Vladimir Tyurin

2

1Kazan E.K. Zavoisky Physical-Technical Institute, Russian Academy of Sciences, 420029,

Sibirsky trakt 10/7, Kazan, Russia 2A.N. Frumkin Institute of Physical chemistry and Electrochemistry RAS, 119071,

Leninsky prospect 31-4, Moscow, Russia


Knowledge of energy transfer processes in multichromophoric assemblies is essential for

biomimetic modeling of energy conversion, and the design and development of supramolecular

systems based on biological pigment, materials chemistry, and optoelectronics [1-3]. Designing

supramolecular compounds for such applications will request the possibility to modulate of spin-

spin interaction between molecular moieties in such system. Most of these systems contained

differently substituted porphyrins. This is because porphyrins possess high stability in different

solvents over a wide range of temperatures, suitable redox properties, and a large quantum yield of

the longlived triplet state formation.

We have investigated a set metalloporhyrin with different metal ion and multiporhyrin for the

purpose of to follow regularities and features of photoinduced spin states of pophyrin based

complex system. Particular attention is paid to interaction between photoinduced triplet state and

paramagnetic ion in the different assemblies. In addition, we attend the significance of this

interaction on formation a spin polarization and the time live of photoinduced spin states. In this

study, we present results of the investigation by EPR method. Combination of CW time-resolved

EPR and pulse EPR allowed to describe the photoexcited spin states in such systems [4].

References:

1. Frischmann, P. D.; Mahata, K.; Würthner, F. Chemical Society Reviews 2013, 42, 1847-1870. 2. Tanaka, T.; Osuka, A. Chemical Society Reviews 2015, 44, 943-969. 3. Pengxia, L.; Du, Z.; Wang, D.; Yang, Z. et al. ChemPhysChem 2014, 15, 3523-3529. 4. Sukhanov, A. A.; Konov, K. B.; Salikhov, K. M.; Voronkova, V. K. et al. Applied Magnetic Resonance 2015, 46,

1199-1220.

Acknowledgements:

We are grateful to the Russian Foundation for Basic Research (project no. 16-03-00586-А) and Program of the

Presidium of RAS №26 for partial financial support.

OR-41


94

Multifrequency EPR of thermo- and photoswitchable copper-nitroxide-based

molecular magnets

Sergey L. Veber,1,2

Matvey V. Fedin,1,2

Elena G. Bagryanskaya2,3

and Victor I. Ovcharenko1

1International Tomography Center SB RAS, 630090 Novosibirsk, Russia

2Novosibirsk State University, 630090 Novosibirsk, Russia

3N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, 630090 Novosibirsk, Russia


Copper-nitroxide-based molecular magnets of the Cu(hfac)2LR family (where hfac is

hexafluoroacetylacetonate and LR is a pyrazolyl-substituted nitroxide ligand) are interesting and

appealing systems exhibiting various magnetic anomalies triggered by temperature or light, which

can generally be viewed as spin-crossover-like phenomena. Significant structural rearrangements

accompany magnetic anomalies in Cu(hfac)2LR and lead to considerable crystal volume changes.

Taking into account the reversibility of these changes, complexes of Cu(hfac)2LR family are often

called “breathing crystals” [1].

The presence of paramagnetic copper(II) ions and stable nitroxide radicals in the polymer

chains of breathing crystals makes EPR widely applicable to these systems. In addition to the

determination of typical parameters (g-tensor and hyperfine splitting constants), EPR allows the

monitoring of magnetostructural switching between different states [2] and evaluation of exchange

interactions in the exchange-coupled clusters of copper(II) with nitroxides [3] and those between

the exchange-coupled clusters. Multifrequency EPR (9-244 GHz) was found very useful and

informative for disentangling different interactions in breathing crystals [4].

This talk highlights the capabilities of multifrequency EPR in investigations of breathing

crystals and related exchange-coupled systems and obtaining crucial information on magnetic

interactions inaccessible by other techniques.

References:

1. V.I. Ovcharenko, E.G. Bagryanskaya, in: M.A. Halcrow (Ed.), Spin-Crossover Materials: Properties and Applications, first ed., John Wiley & Sons, Ltd., 2013, 239–280.

2. S.L. Veber, M.V. Fedin, K.Y. Maryunina, A. Potapov, D. Goldfarb, E. Reijerse, W.Lubitz, R.Z. Sagdeev, V.I. Ovcharenko, E.G. Bagryanskaya, Inorg. Chem. 2011, 50, 10204.

3. S.L. Veber, M.V. Fedin, A.I. Potapov, K.Y. Maryunina, G.V. Romanenko, R.Z.Sagdeev, V.I. Ovcharenko, D. Goldfarb, E.G. Bagryanskaya, J. Am. Chem. Soc. 2008, 130, 2444.

4. M.V. Fedin, S.L. Veber, E.G. Bagryanskaya, V.I. Ovcharenko, Coord. Chem. Rev. 2015, 289, 341.

Acknowledgements:

This work has been supported by the RFBR (grants No. 14-03-00224 and 15-03-07640) and the RSF (grant No 14-13-

00826).

OR-42

POSTERS


95

Alamethicin-Induced Homogenization of Model Biological

Membrane by Pulse EPR

Ekaterina Afanasyeva, Victoria Syryamina, Nikolay Isaev, Sergei Dzuba

Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya-3, Novosibirsk, 630090, Russia, and

Novosibirsk State University, Pirogova-2, Novosibirsk, 630090, Russia


Bacterial mutations result in ineffectiveness of common antibiotics causing a resistance of

bacteria against most of them; which arises as is a serious problem in a current-day medicine. The

new family of therapeutic agents is antimicrobial peptides that endowed of membrane-modifying

properties and disrupt the structure and functioning of cellular membrane. Membrane-protein

interactions are actively studied by different techniques, but the molecular mechanisms of

antimicrobial action are still heavily debated.

Peptide alamethicin, isolated from Trichoderma viride, exhibits a progressive antimicrobial

activity that is explained by switching from the planar to transmembrane orientation, with its

concentration increasing, and accompanying by aggregation at some critical concentration.1

However, the membrane-perturbation effects were observed also below this critical

concentration.2,3

Therefore, the main goal of this work is studying the influence of alamethicin on

the model membrane structure at peptide to lipid molar ratio of 0.1-5%. The model membrane was

prepared from monounsaturated lipids with stearic acids spin-labeled at the 5th

or 16th

carbon

positions along the acyl chain.

Natural alameticin was studied, isolated from Trichoderma viride:

Ac-Aib-Pro-Aib-Ala-Aib-Ala-Gln-Aib-Val-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-Gln-Gln-Phl

Pulse EPR methods was used for studying electron-electron (e-e) dipole-dipole interactions

employing effects of so called “instantaneous spectral diffusion” in electron spin echo (ESE) decay,

and electron-nuclei (e-n) dipole-dipole interactions employing effects of ESE envelope modulation

(ESEEM). The e-e interaction is sensitive to the spin label local concentration, while e-n interaction

are informative about water penetration in the membrane core.

It was found in preceding experiments that spin-labeled stearic acids strongly self-associate in

membrane, increasing its local concentration by an order of magnitude. The presence of alamethicin

however destroys these local clusters, with stearic acids becoming distributed uniformly in the

membrane. This effect appears even at very small peptide concentration in membrane, about ~ 0.1

mol. %. The water concentration membrane profile under alamethicin action increases, that means

the loosening package of membrane polar region. Effects of homogenization structure coupled with

loosening package of model biological membrane may provide an important antimicrobial

mechanism of alamethicin action.

References

1. Salnikov et al. J. Phys. Chem B, 2009, 113(10), 3034-3042. 2. Bortolus M. et al. Biochim. Biophys. Acta (BBA)-Biomembr. 2013 1828(11), 2620-2627. 3. Qian S. et. al. J. Phys. Chem. B, 2014 118(38), 11200-11208

Acknowledgements

This work was supported by the Russian Science Foundation, project # 15-15-00021.

PO-01



96

Highly sensitive measurement of MFE for probing electron spin dynamics of

intermediate biradical in flavin adenine dinucleotide

Kazuya Arakawa,1 Kiminori Maeda,

1 Jonathan R. Woodward

2

1Department of Chemistry, Graduate School of Science and Engineering, Saitama University,

Saitama 338-8570, Japan. 2Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan.


The magnetic field effects (MFEs) on the

photochemical reaction of flavin containing blue light

receptor have been gotten a great attention from

interests in the magnetoreception of animals.

However, conventional transient absorption

techniques are sometimes not enough sensitive to

detect MFEs in biological samples. Recently, we

improved the sensitivity by means of collinear two

colour CW laser irradiation coupled with auto-

balanced detection. The test results by the setup in

the photo-induced intramolecular electron transfer

reaction of Flavin Adenine Dinucleotide(FAD) is

presented[1].

The new setup is detectable the extinctions of

~10-4

synchronized with modulation of the exciting

blue light. The signal is stable that a single 2 min

magnetic field scan was sufficient to obtain the MFE

curves as shown in Fig.1.

The solutions including free Tryptophan(Trp) as a

quencher are also investigated[2]. The sensitivity and

stability of the present technique enables us to

measure the B1/2 in very high resolution. Trp

concentration dependence of B1/2 values is shown in

Fig.2. In order to clarify the mechanism of this B1/2

change by quencher concentration, we constructed a

novel time resolved setup with a balanced detector

and succeeded to measure the time resolved 2D-

MARY spectrum (time and magnetic field) as shown

in Fig.3.

References: 1. M. Murakami, K. Maeda, T. Arai, J. Phys. Chem. A 109, 5793-5800(2005). 2. D.A. Dodson, C.J. Wedge, M. Murakami, K. Maeda, M.I. Wallece, P.J. Hore, Chem.Comm. 51, 8023-8026(2015).

Fig. 1. MFE curves observed using the

newly installed setup

Fig. 2. Quencher concentration dependence

of B1/2

Fig. 3. Time resolved MFE spectrum

(2D-MARY)

PO-02



97

Portable Coherent Superheterodyne X-band EPR Spectrometer

Alexander Rokeakh, Mikhail Artyomov

Institute of Natural Sciences, Ural Federal University, 19 Mira Street, Yekaterinburg, 620002, Russia


The EPR spectrometer, which uses superheterodyne principle of signal receiving, allows registering

absorption spectrum (but not derivative-like spectrum) with sufficiently high sensitivity and without any

modulation distortions. In addition, such spectrometer allows to register both extremely narrow

(resolution is determined by magnetic field homogeneity only) and extremely wide signals. Appliance

complexity, tedious usage, instability and low immunity to external influences (temperature, vibrations,

etc.) prevented commercial scale production of ones.

Impressive evolution of circuit technology and design for the needs of communication mainly,

which took place in few last decades, allows to revise the possibilities of successful usage of

superheterodyne principle on the EPR equipment field. J.S. Hyde with coworkers [1] noted this

development prospect and proposed four registration structures, two of them (2 and 3) are

superheterodynes.

Present work is devoted to development of industry-oriented portable coherent superheterodyne X-

band EPR spectrometer corresponding to Class 2 [1]. The base concept of design is explained in work

[2]. Spectrometer operates in narrow vicinity of 9200MHz with IF equal to 100MHz. The whole

microwave part of instrument with the exception of the sample rectangular cavity TE102 (further it is

planned to use LGR as well) and matching unit is implemented as compact inexpensive untunable

microstrip modules on the base of commercial microwave ICs and low cost Rogers PCBs. The

microwave Master Oscillator (MO) generates probing wave with user controlled power which incidents

to sample cavity and IF reference mixer. The Local Oscillator (LO) produces wave 9300MHz (when

MO frequency is equal 9200MHz), locked to IF reference by PLL. Because IF reference is produced by

mixing LO output with probing wave at current power (after attenuator, which shifts MW phase), phase

relations are aligned for any power level.

The information IF signal is complex and composed by absorption and dispersion components,

which are separated by quadrature demodulation. The dispersion component also contains information

on mutual detuning of the MO frequency and the resonant frequency of the sample cavity and so it is

used for AFC MO frequency to resonant frequency of the sample cavity. Besides there is mode of MO

frequency stabilization to stable crystal reference oscillator by PLL. This reference oscillator is single

source for synthesis of the all frequencies necessary for spectrometer operation.

Digital signal processing, processor control system, network interface with PC for the most part are

implemented in FPGA crystal. The compact magnet on the base of permanent magnets SmCo with

additional coils for scanning of the field has inhomogeneity about 30ppm was used. For magnetic field

induction measurements serves precision ingenious magnetometer on the base of Hall effect.

For recording of conventional EPR spectra, dedicated coils superimpose low frequency field

modulation. The Modulation signal is produced by DDS with a frequency equal to an integral

submultiple of ADC sampling frequency.

In addition, the spectrometer has the ability of fast transient process recording with high time

resolution.

References:

1. J.S. Hyde, T.G. Camenisch, J.J. Ratke, R.A. Strangeway, W. Froncisz in: Eaton, S.S., Eaton, G.R., Berliner, L.J. (eds.) Biomedical EPR, part B: Methodologies, Instrumentation, and Dynamics. Biological Magnetic Resonance, vol. 24, p. 199. Kluwer Academic/Plenum, New York (2004)

2. A.I. Rokeakh, A.M. Batin, O.B. Makhnev, A.A. Mekhonoshin, Yu.A. Sherstkov, A.A. Lisitsin, and V.Yu. Yazan, Appl. Magn. Reson., 1995, 9, 441-457.

PO-03


98

Spin Probe ESR Detected Dynamics of Interstitial Supercooled Water

Debamalya Banerjee,1 S.N. Bhat,

2 S.V. Bhat

2 and Dino Leporini

3,4

1Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302, India

2Department of Physics, Indian Institute of Science, Bangalore 560 012, India

3Dipartimento di Fisica ”Enrico Fermi”, Universit`a di Pisa, Largo B. Pontecorvo 3, Pisa, Italy

4IPCF-CNR, Uos Pisa, Pisa, Italy


Using electron spin resonance (ESR) spectroscopy, we have demonstrated two different

mobilities for spin probe TEMPOL dissolved in deeply supercooled interstitial water in ice matrix.

This was achieved by quenching (to 4.2K) and subsequent slow reheating (QRW protocol) of water

sample in a capillary. We have found that two mobilities are the evidence of two co-existing liquid

phases, one ordered low density liquid (LDL) and another disordered high density liquid (HDL). It

is also possible to reach the supecooled regime of water by slow cooling from room temperature

(SC protocol), which reveals suppression of the ordered water fraction. Given that the volume and

geometry of interstitial space in ice matrix depends strongly on the thermal history, we argue that

the SC protocol leads to tighter confinement of water than QRW protocol suppressing the LDL

fraction in it. Compelling evidence of the presence of ice-like regions is provided by the probe’s

orientational entropy barrier. Calculation shows that in samples prepared by QRW protocol, the

entropy barrier surmounted by the slower probe fraction exceeds that of equilibrium water by the

melting entropy of ice, whereas no increase of the barrier height is observed under stronger

confinement (SC protocol).

References:

1. Banerjee D, et al. (2009) ESR evidence for 2 coexisting liquid phases in deeply supercooled bulk water. Proc. Natl. Acad. Sci. USA 106: 11448-11453

2. Banerjee D, et. al. (2012) Molecular probe dynamics reveals suppression of ice-like regions in strongly confined supercooled water. PLoS one 7:e44382

PO-04

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0044382

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0044382


99

Magnetic behavior peculiarities of heterometallic Cu-Pb complex

Alexey S. Berezin, Vladimir A. Nadolinny, Vladislav V. Krisyuk

Nikolaev Institute of Inorganic Chemistry SB RAS, Av. Lavrentyev 3, Novosibirsk, 630090, Russia


The newly copper-lead heterometallic dimer complex with dipivaloylmethane and

hexafluoroacetylacetone ([Cu(dpm)2Pb(hfa)2]2) was synthesized with triclinic symmetry (P-1).

Room temperature Q-band EPR spectrum is described by spin-Hamiltonian �̂�𝑠 = 𝛽𝑯𝑔�̂� +

𝐷 (�̂�𝑧

2−

1

3𝑆(𝑆 + 1)) + 𝐴�̂�𝐼 ̂ with S=1, g||=2.262, g┴=2.054, A||=156 G and A┴=20 G from two

equivalent copper ions, weak dipole-dipole (D=20 G) and weak exchange interactions. Below

110 K, only dipole-dipole interaction is observed with no exchange interaction. At 10 K Q-band

EPR spectrum is described by same spin-Hamiltonian with S=1, g||=2.260, g┴=2.050, A||=186 G and

A┴=20 G, and D=70 G. The magnetic susceptibility from 110 to 400 K contains both paramagnetic

and ferromagnetic contributions; there is a magnetic behavior anomaly near the 110 K. It is

assumed that above 110 K the weak indirect exchange interaction exists between copper ions in

dimer through groups of oxygen and lead atoms and below 110 K this interaction disappears. The

crystal structure parameters change with temperature (accompanied by a color change), the

restructuring of the system occurs and, consequently, the indirect exchange interaction transforms.

The observed effects are reversible.

Figure 1. Structure of [Cu(dpm)2Pb(hfa)2]2 along a. H atoms are hidden for clarity.

Acknowledgements This research was financially supported by the Russian Foundation for Basic Research (grant nos. 15-03-00878 a).

PO-05



100

Singly-Bonded [60]Fullerene Dimers Studied by in situ EPR Spectroscopy

Wenqi Liu, Jiafu Chen and Jihu Su

Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of

China, Hefei, Anhui 230026, People’s Republic of China


Molecular devices have been studied and applied because of supplying high-performance

analytical systems and wide applications. A great effort has been made on fullerene molecules and

their derivatives. For [C60]fullerene, an intercage C-C bond is found to be formed in the

[C60]fullerene dimer, and the dimerization can be promoted by the manganese(III)-catalyzed

acetate-mediated reaction.

Since the fullerene oligomer is not stable, the thermodynamics property of this intercage C-C

bond is not clear when compared to the C-C bond in the organic community. This, however, has not

been studied, which might be of importance as a very fundamental and crucial question.

Chemically, the different stability of C-C bond gives to the different property and application of the

related complex. In the present study, this question was stressed, and investigated by the X-band in

situ variable-temperature electron paramagnetic resonance (EPR) spectroscopy. The EPR signal

intensity as a function of the heating temperature displayed that the BDE (Bond Dissociation

Enthalpy) value of this single C-C bond was 72.4 ± 0.6 kJ/mol (17.3 ± 0.15 kcal/mol). The value

was only about twice the typical hydrogen bonds, or one fifth of those in the diamond or the

saturated hydrocarbons. The data showed that the intercage C-C bond was unusual weak. Based on

this thermodynamic property, the [C60]fullerene dimer can be used to prepare the aligned fullerene

molecule on the anticipated supporting base.

References:

1. G. W. Wang, C. Z.Wang, S. E. Zhu, Y.Murata, Chem Commun, 2011, 47, 6111-6113. 2. V. Balzani, A. Credi, M. Venturi, Molecular Devices and Machines : Concepts and Perspectives for the Nanoworld,

2nd ed.; Wiley-VCH: Weinheim, 2008 3. S. R. Lu, T. N. Jin, E. Kwon, M. Bao, Y. Yamamoto, Angew Chem Int Edit, 2012, 51, 802-806.

Acknowledgements

This work was financially supported by the Specialized Research Fund for the Doctoral Program of Higher

Education and National Natural Science Foundation of China.

PO-06


101

EPR and optical absorption studies of Cr3+

doped cesium tetrabromozincate

Ram Kripal, Awadhesh Kumar Yadav and Prashant Dwivedi

EPR Laboratory, Department of Physics, University of Allahabad, Allahabad-211002,

Physics Department,kali chran Nigam Institute of technology ,Banda21001 India

India Tel: 91-532-2470532; Fax: 91-532-2460993

E-mail: [email protected], [email protected], [email protected]

Electron paramagnetic resonance (EPR) study of Cr3+

doped cesium tetrabromozincate (CTBZ)

single crystal is done at room temperature. The hyperfine structure for Cr53

isotope is also obtained.

Two magnetically inequivalent sites for Cr3+

are observed. The spin Hamiltonian parameters are

evaluated as: D = 234×10-4

cm-1

, E = 69×10-4

cm-1, g = 2.0104, A = 80×10

-4 cm

-1 for site I and D =

235×10-4

cm-1

, E =70×10-4

cm-1

, g = 2.0061, A = 82×10-4

cm-1

for site II, respectively. The optical

absorption spectra are recorded at room temperature. The energy values of different orbital levels

are determined. The values of various parameters obtained are: B = 602 cm-1

, C = 2504 cm-1

, Dq =

1870 cm-1

, h = 1.63 and k = 0.21, where B and C are Racah parameters, Dq is crystal field

parameter, and h and k are nephelauxetic parameters, respectively.

Keywords: A. Inorganic compounds; B. Crystal growth; D. Crystal fields; D. Electron

paramagnetic resonance; D. Optical properties.

References: 1. C. Rudowicz, R. Bramley, J. Chem. Phys. 83 (1985) 5192- 5197. 2. C. Rudowicz, Y. Y. Zhao, W. L. Yu, J. Phys. Chem. Solids 53 (1992)1227-1236. 3. D. S. Schonland, Proc. Phys. Soc. 73 (1958) 788-792 4. W. C. Zheng, S. Y. Wu, Phys. Stat. Solidi B 207 (1998) 429-435. 5. P. W. Atkins, T. L. Overton, J. P. Rourke, M. T. Weller, F. A. Armstrong, Inorganic Chemistry, 5

th Ed., Oxford

University Press, 2010. 6. R. J. Peruma Reddy, Coordin. Chem. Rev. 4 (1969)73-105. 7. Y. Tanabe, S. Sugano, J. Phys. Soc. Jpn. 9 (1954)753-766. 8. F. Rasheed, K. P. O Donnel, B. McCollum, B. Henderson, D. B. Hollis, J. Phys. : Condens. Matter 3 (1991) 1915-

1930. 9. C. E. Moore, Atomic Energy Levels, (Chromium through Niobium), National Bureau of Standard Circular No. 467,

Vol. 2, US Government Printing Office, Washington, DC, 1948, 1952. 10. R. V. S. S. N. Ravi Kumar, A. V. Chandrasekhar, S. N. Rao, N. Madhu, B. J. Reddy, Cryst. Res. Technol. 34 (1999)

911-914. 11. K. T. Liu, J. T. Yu, S. H. Lou, C. H. Lee, Y. Huang, K. H. Li, J. Phys. Chem. Solids 55 (1994)1221-1226. 12. W. Seeber, D. Ehrt, D. Eberdorff-Heidepriem, J. Non-Cryst. Solids 171 (1994) 94-104. 13. C. K. Jorgensen, Absorption Spectra and Chemical Bonding in Complexes, Plenum, Oxford, 1962, p. 113. Acknowledgements:

The authors are thankful to the Head, SAIF, I.I.T. Mumbai, Powai, Mumbai for providing the facility of EPR

spectrometer. One of the authors, Awadhesh Kumar Yadav is thankful to the Head, Department of Physics,

University of Allahabad, Allahabad for providing departmental facilities.

PO-07



102

Trityl-based alkoxyamines: C—ON bond homolysis for potential NMP

controllers and spin-labels

Gérard Audran,1 Elena G. Bagryanskaya,

2,3 Paul Brémond,

1 Mariya Edeleva,

2 Sylvain R. A.

Marque,1,2

Dmitriy Parkhomenko,2 Olga Yu. Rogozhnikova,

2,3 Victor M. Tormyshev,

2,3 Evgeny

Tretyakov,2 Dmitry V. Trukhin,

2,3 and Svetlana Zhivetyeva

2

1 Aix-Marseille Université, CNRS, ICR, UMR 7273, case 551, Avenue Escadrille Normandie-Niemen, 13397

Marseille Cedex 20 France. 2 N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, 630090

Novosibirsk, Russia. 3Novosibirsk State University, Pirogova 2, Novosibirsk. 630090, Russia

Persistent trityl radicals Ar3C• have been discovered by Gombert in 1900. Currently they are

used as spin probes to investigate pH changes in vivo, to investigate protein structures through

distance measurements. Very recently, the preparation of nitroxide-trityl radical dual probes has

been reported and raised a keen interest as probes due to the modulation of the exchange interaction

between the two spins and as polarizing agent for Dynamic Nuclear Polarization-enhanced NMR

(DNP-NMR). In the same period, an increasing interest on the applications of bisradicals such as

bisnitroxides appeared due to their applications as initiator/controller agent in Nitroxide Mediated

Polymerization (NMP) and as polarizing agent in DNP-NMR. Moreover, since 3 decades, the

chemistry of alkoxyamine R1R2NOR3 has been developed for their application as controller/initiator

for NMP. Very recently, new applications emerged in Materials Sciences – as key moieties in self-

healing polymer, as fluorescent switches, and as coding system – as well as in Biology as a new

type of agents for Theranostic.

Taking into account the highly valuable properties of trityl radicals as spin probes and the

potential of application of alkoxyamines as well as their various modes of activations – protonation,

oxidation, alkylation, light irradiation – the investigation of the properties of trityl – attached

alkoxyamines is timely due. Hereafter, we reported the first preparation of several trityl-

alkoxyamines based on the SG1 and TEMPO nitroxyl fragments (Figure 1), the homolysis rate

constant kd of the C—ON bond as well as the EPR features of the trityl-TEMPO and trityl-SG1

biradicals. Interestingly, the trityl radical has no significant effect on kd meaning that these

alkoxyamines kept all their kinetic properties to be applied as controller/initiator in NMP, as switch

in optotronic, and as theranostic agents.

Figure 1. Trityl-alkoxyamines based on the TEMPO (1) and SG1 (2) nitroxyl fragments

Acknowledgements:

This work has been supported by the Russian Science Foundation (grant № 15-13-20020)

PO-08



103

Electron paramagnetic resonance of 157

Eu2+

-doped yttrium aluminum garnet

A.V. Fokin,1 V.A. Vazhenin,

1 A.P. Potapov,

1 M.Yu. Artyomov,

1 H.R. Asatryan,

2

A.G. Petrosyan3 and K.L. Ovanesyan

3

1Ural Federal University, 19 Mira Street, Yekaterinburg, 620002 Russia

2Ioffe Institute, St. Petersburg, Russian Federation

3Institute for Physical Research, NAS of Armenia, Ashtarak-2, Armenia


Single crystals of garnets doped by rare-earth ions are interesting as laser materials and

phosphors for LEDs. In the previous work [1], the electron paramagnetic resonance of Eu2+

and

Gd3+

centers (S=7/2, local symmetry D2) was studied in single crystals of yttrium aluminum garnet

which was doped by rare-earth ions with a natural abundance of isotopes.

In this work, the Y3Al5O12 single crystals were grown by method of vertically oriented

crystallization from the melt and doped by europium impurity with enriched 151

Eu isotope in order

to avoid the overlapping of hyperfine structure components in EPR spectra. The isotopic

composition of the used Eu2O3 oxide was 151

Eu (97.5%) and 153

Eu (2.5%). Tetravalent impurities in

the form of oxides SiO2 or HfO2 (0.2 at.%) were added into the melt for a stabilization of high

density of Eu2+

(0.2 at.%) ions.

The EPR measurements were performed on an X-band EMX Plus Bruker spectrometer in the

temperature range of 120-300 K. The europium ions replace of yttrium in positions with local

symmetry D2. As a result, in EPR spectra, it was observed the six magnetically nonequivalent

centers which combine into equivalent groups in orientations B||C2, B||C3 and B||C4 (B is the

magnetic field induction, Ci – axes of crystal symmetry). In three magnetic field orientations (B||С2,

B||С4 and B||С3) the frequency, temperature and orientation (near these directions) dependences of

signal positions of 151

Eu2+

centers were investigated. The parameters of orthorhombic spin-

Hamiltonian [2] were calculated by the least square method with using of hyperfine structure

components’ positions at 120, 200 and 300 K (at 300 K: b20 = -8940 MHz, b22 = -9030 MHz, b40 =

30MHz,

b42 = -950 MHz, b44 = -840 MHz, Ax=Ay=Az = -102 MHz, g = 1.9905). Taking into account the

negative sign of hyperfine coupling parameter which was determined in works [3-5] the relative

signs of the fine and hyperfine structure parameters were obtained from a comparison of an

experimental and simulated spectra with hyperfine structure formed by allowed and forbidden

electron-nuclear transitions at B||C4 and 300 K.

The research was performed within the state task of the Russian Ministry of Education and

Science; measurements were carried out using equipment of the Centre of Shared Use ‘Modern

Nanotechnologies’of the Ural Federal University.

References: 1. V.A. Vazhenin, A.P. Potapov, H.R. Asatryan, Y.A. Uspenskaya, A.G. Petrosyan, A.V. Fokin. Fiz. Tverd. Tela, 2016,

58, 1573-1579 (in Russian) 2. S.A. Al’tshuler and B.M. Kozyrev, Electron Paramagnetic Resonance (Academic, London, 1964; Nauka, Moscow,

1972), p.121. 3. J. Bronstein, V. Volterra, Phys. Rev., 1965, 137, A1201-A1204. 4. J.S.M. Harvey, H. Kiefte, Canad. J. Phys., 1969, 47, 1505-1515. 5. A.D. Gorlov, Phys. of Solid State, 2014, 56, 2185-2190.

PO-09


104

Low-Temperature Dynamical Transition in Lysozyme by

Pulsed EPR of Spin Labels

E. A. Golysheva, S. A. Dzuba

Physics Department, Novosibirsk State University, 630090, Novosibirsk, Russia, and

Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, 630090,

Novosibirsk, Russia


The relationship between structural-dynamical properties and physiological activity of

biological systems currently is a subject of intensive investigations. Neutron scattering and

Mössbauer absorption studies of atomic vibrations in biological systems show that vibrations are

harmonic at low temperatures and become anharmonic (or diffusive) above some temperature lying

between 180 and 230 K. For proteins, this phenomenon is called protein dynamical transition.

Protein dynamical transition may be investigated also by pulsed electron paramagnetic

resonance (EPR) of spin probes and labels. The advantages of pulsed EPR are the sensitivity to the

orientation motion of molecules and relative simplicity of the experiment. Using site-directed spin

labeling, it is possible to study different parts of complex supramolecular structures.

Here, lysozyme with different water content (h = 0; 0.1; 0.2) was studied between 80 and 270

K. Samples were prepared with TEMPON nitroxide or spin-labeled stearic acid incorporated. From

electron spin echo decays the anisotropic spin relaxation rate, 𝑊𝑎𝑛𝑖𝑠, was refined which is induced

purely by orientational motion of a molecule. The temperature dependences obtained (see Fig. 1)

demonstrate a drastic increase of the 𝑊𝑎𝑛𝑖𝑠

above 140 K for the hydrated lysozyme

sample and only a monotonic increase for

the dry lysozyme sample. The results are

discussed in relation with the literature

neutron scattering data.

100 150 200 250

0,0

0,5

1,0

1,5

2,0

2,5 lysozyme with tempon (h=0.1)

lysozyme with tempon (h=0)

lysozymewith stearic acid (h=0.2)

Wa

nis,

s-1

T,K

Fig. 1

PO-10



105

Investigation of Grain Size Effect on the Properties of Sm0.08Ca0.92MnO3

Lora Rita Goveas,1 K.N. Anuradha

2 and S.V. Bhat

3

1Department of Physics, St. Joseph’s College, Bangalore-560027, India

2Department of Physics, Dr. Ambedkar Institute of Technology, Bangalore-560056, India

3Department of Physics, Indian Institute of Science, Bangalore-560012, India


Properties of doped rare earth manganites (T1-xDxMnO3, where T is a trivalent rare earth ion

and D a divalent alkali earth ion) are found depend considerably on the size of the particles [1].

Neutron powder diffraction, electron microscopy, transport and magnetic measurements, prove that

magnetic state of bulk Sm1-xCaxMnO3 (x ~ 0.9) is phase separated, with TN = TC = 110 K, and

consists of FM regions embedded AFM matrix [2].Here we present a comparative study of the

temperature dependent magnetic properties and EPR parameters of nanosized and bulk samples of

Sm0.08Ca0.92MnO3. Nanoparticles (mean diameter ~ 27, 22 and 16 nm) were synthesized by sol-gel

technique and the bulk samples were obtained by sintering the nanoparticles at high temperatures.

The samples were characterized by XRD, EDAX and TEM. The magnetic measurement carried out

by SQUID magnetometer showed that the nanoparticles underwent ferromagnetic transition (TC) at

103 K where as the bulk sample showed the same at 105 K. The field cooled curve shows that the

magnetization decreases with the size reduction. The zero field cooled curve indicates a spin glass

transition in the case of nanosamples. The Electron Magnetic Resonance (EMR) studies carried out

between the temperatures 4-300K confirm the existence of ferromagnetism in the bulk sample as

well as in nanosamples but with a weakened strength which is indicated by the EMR intensity

shown in figure (i) . EMR signals are observed from 300 K till 5 K in the case bulk samples where

as in the case of nanosamples signals get weaker below 50 K indicating the weakening of FM phase

in them. In manganites linewidth shows a characteristic minimum near 1.1 TC where TC is the FM

transition temperature[3]. We observe this minimum becomes less shallow as the size decreases as

shown in figure (ii). The magnetic behaviour of the nanoparticles is ascribed to core shell scenario;

reduction of magnetization in the nanoparticles is due to uncompensated surface spin.

Figure (i): Temperature variation of g-factor Figure (ii): Temperature variation of Line width

References:

1. L. R. Goveas, K. N. Anuradha, K. S. Bhagyashree, and S. V. Bhat, J. Appl. Phys., vol. 117, 17, 2015. 2. C. Martin, A. Maignan, M. Hervieu, B. Raveau, Z. Jirak, et al., Phys. Rev. B, vol. 62, 10, p. 6442, 2000. 3. F. Rivadulla, M. A. López-Quintela, L. E. Hueso, J. Rivas, et al.,Phys. Rev. B vol. 60, 11922 , 1999.

PO-11


106

On-line Detection of Antioxidant Ability by LC-ESR-MS

Hideyuki Hara,1 Haruo Hosoda

2

1ESR Application, Bruker BioSpin K.K.,3-9Moriya-cho, Kanagawa-ku, Yokohama-shi,

Kanagawa 221-0022, JAPAN 2ESI Application, Bruker Daltonics K.K.,3-9Moriya-cho, Kanagawa-ku, Yokohama-shi,

Kanagawa 221-0022, JAPAN


Antioxidant molecules themselves are typically not free radicals and are not ESR-active.

However, these compounds do react rapidly with reactive oxygen species (ROS) and other free

radicals to render them harmless. The ESR-based DPPH assay can be used to provide quantitative

information concerning the relative effectiveness of various dietary substances and their antioxidant

capacities. In this report, we construct the LC-ESR-MS system and determined the antioxidant

ability of each element of various beverages.

An HPLC(Agilent LC1100) was connected with the ESR (Bruker, EMXnano) and another

pump for the DPPH solution was connected after UV detection. The sample was then mixed and

pumped into the flow cell of the ESR. MS spectometer (Bruker, Compact) was also connected after

UV detection and can get mass spectrum for antioxidant activities which are detected by LC-ESR

directly.

The figures show the UV-HPLC chromatogram (blue) and the ESR DPPH chromatogram (red)

for the coffee and green tea samples. In both HPLC chromatograms, the highest peak shows the

Caffeine but there is no response in the ESR DPPH chromatogram, thus Caffeine shows no

antioxidant activity. In coffee there are many different polyphenols that show an antioxidant activity

as seen by the peaks in the ESR chromatogram. In Green tea, the antioxidant activity is from the

many kinds of Catechin present. The LC-ESR method reveals the antioxidant activity of each

component in the sample.

Fig. 1 (left) ESR (red) and HPLC (blue) chromatogram of coffee

Fig. 2 (right) ESR (red) and HPLC (blue) chromatogram of green tea

To determin the compound formula and structure, MS

spectrum was measured with peak#1 in green tea

sample(Fig.3). Antioxidant compound gallocatechin were

identified by mass and fragment spectrum via compounds

library(KEGG search, etc.)

Fig. 3 MS spectrum of peak#1 in Green Tea

PO-12


107

One-electron electrochemical oxidation and reduction of the first C(sp2)-coupled

nitronyl nitroxide diradical

L.A. Shundrin,1 I.G. Irtegova,

1 N.V. Vasilieva,

1 E.V. Tretyakov,

1 E.M. Zueva,

2 V.I. Ovcharenko

3

1 N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences,

Academician Lavrent’ev Avenue, 9 , 630090 Novosibirsk, Russian Federation 2 Department of Inorganic Chemistry, Kazan National Research Technological University, Marx Str., 68 K,

420015 Kazan, Russian Federation 3 International Tomography Center, Siberian Branch of the Russian Academy of Sciences, Institutskaya Str.,

3a, 630090 Novosibirsk, Russian Federation


Interest in nitronyl nitroxide (NN) radical family has increased over the last two decades in

view of the development of molecular based magnets1. The electrochemistry of NN or NN

polyradicals is also of interest because they are able to undergo electrochemical reversible

oxidation, giving molecular ions of different multiplicities2.

N-[bis(4,4,5,5-tetramethyl-3-oxido-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)methylene]-2-methyl-

propan-2-amine oxide (1), which is the first representative of a C(sp2)-coupled NN diradical

3, can

be reversibly oxidized in MeCN − 0.1 M Et4NClO4 via an EE-process into the corresponding

radical cation 2 and oxoammonium dication 3, and quasi-reversibly reduced to give the radical

anion 4. For the latter process the heterogeneous rate constant (ks) of quasi-reversible electron

transfer was calculated to be equal 0.0022 ± 0.0002 cm s-1

at 295 K.

Both paramagnetic molecular ions 2 and 4 can be easily generated by electrolysis at the

corresponding peak potentials and have sufficiently long life-times to measure their EPR spectra in

MeCN3. The possibility to generate the RA 4 is determined by quasi-reversible electron transfer

during the first step of the ECR of 1, which is not accompanied by subsequent chemical processes.

The HFCC values in EPR spectra of 2 (aN, mT: 0.724 (2N), ~0.017 (2N), 0.06 (1N)) and 4 (aN,

mT: 0.746 (2N), ~0.024 (2N), 0.085 (1N)) along with corresponding DFT calculations (geometry

optimi-zation in MeCN with subsequent calculation of HFCC) demonstrate a dominant location of

the unpaired electron at one NN fragment of the molecular ions, indicating the hindered rotation of

the two cyclic fragments.

References:

1. J.S. Miller, M. Drillon, Magnetism: Molecules to Materials, Wiley-VCH: New York, 2005, V. I–V. 2. G. Harada, T. Jin, A. Izuoka, M. M. Matsushita, T. Sugawara, Tetrahedron Lett., 2003, 44, 4415. 3. S. Tolstikov, E. Tretyakov, S. Fokin, E. Suturina, G. Romanenko, A. Bogomyakov, D. Stass, A. Maryasov, M. Fedin,

N. Gritsan, V. Ovcharenko, Chem. Eur. J. 2014, 20, 2793. 4. L.A. Shundrin, I.G. Irtegova, N.V. Vasilieva, E.V. Tretyakov, E.M. Zueva, V.I. Ovcharenko, Tetrahedron Lett.,

2015, 56, 1207.

PO-13


108

X-band bismuth germanate dielectric resonator

Mikhail Ivanov,1,2

Sergey Veber,1,2

Elena Bagryanskaya,1,2,3

Matvey Fedin,1,2

Vladimir Nadolinniy,4

Gennady Kuznetsov4

1 Novosibirsk State University, 2 Pirogova Str., Novosibirsk, 630090, Russia

2 International Tomography Center, 3A Institutskaya Str., Novosibirsk, 630090, Russia

3 N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, SB RAS, 9 Ac. Lavrentieva ave.,

Novosibirsk, 630090, Russia 4 Nikolaev Institute of Inorganic Chemistry, SB RAS, 3 Ac. Lavrentieva ave., Novosibirsk, 630090, Russia


Microwave resonator is an important component of an EPR spectrometer, which can be

modified/developed to fit experimental conditions in the best way and thus to increase the

sensitivity of the whole EPR setup. High purity bismuth germanate (Bi4(GeO4)3, BGO) is proposed

and implemented as alternative material for dielectric EPR resonators. In this work we replace the

standard alumina insert in the Bruker X-band ER 4118X-MD-5W1 resonator by BGO of the same

resonant range (X-band) and analyze the CW and pulse EPR performance of such resonators

depending on the dimensions of BGO inserts. The Q-values of empty resonators, B1 saturation

curves and CW EPR spectra of DPPH were measured and analyzed in a temperature range 6-300 K.

The Q-value of BGO insert with ID=2 mm reaches 43 000 at 6 K and exceeds the Q-value of

standard alumina insert by a factor of ~1.5. The performance of BGO dielectric resonator in pulse

EPR experiments was also characterized. The CW EPR baseline measured at 300, 77 and 6 K

confirms the absence of BGO-attributed signals proving the high purity of the material used.

Acknowledgements:


PO-14




109

Assemblies of spin-labeled molecules in model lipid membranes by pulsed EPR

Maria Kardash, Sergei Dzuba

Voevodsky Institute of Chemical Kinetics and Combustion, Novosibirsk, 630090, Russia and

Novosibirsk State University. Pirogova 2, Novosibirsk. 630090, Russia


Membrane heterogeneity is widely investigated for the understanding the cell membrane

properties. In our study, we used electron spin echo (ESE) of spin labels for investigation of

interaction between spin-labeled molecules in a model lipid membrane. This method is sensitive to

interactions at distances of ~ 1-10 nm. 5-DOXYL stearic acid and spin-labeled lipids were used as

spin-labeled molecules, and the model membranes were multibilayers from DOPC lipids.

The found dependence of the ESE decay rate on the spin-labeled lipid 5-DOXYL PSPC molar

concentration is shown in Fig. 1. This dependence is interpreted as a consequence of the formation

of clusters with enhanced local concentration, which is shown schematically in Fig. 2. These

clusters appear at some critical concentration, Ccrit. Above Ccrit, the increase of echo decay rate

occurs from interaction between different clusters. A simple

model for cluster formation predicts that at Ccrit. the local

concentration is ~ 9 times larger than the average

concentration. The average distance between molecules in

clusters is estimated as ~ 3 nm. These results are found to be

similar for both types of spin-labeled molecules and may take

place for other types of guest molecules in the membranes.

Fig. 2

Acknowledgements:

This work was supported by the Russian Foundation for Basic Research, project # 15-03-02186.

Fig.1

PO-15



110

EPR of germanium-vacancy defect in diamond

A.Y. Komarovskikh,1,2

V.A. Nadolinny,1 Y.N. Palyanov,

2 I.N. Kupriyanov,

2

O.P. Yuryeva,1 M.I. Rakhmanova

1

1Nikolaev Institute of Inorganic Chemistry SBRAS, Acad. Lavrentiev Ave. 3, Novosibirsk, 630090, Russia

2Sobolev Institute of Geology and Mineralogy SBRAS, Acad. Koptyuga Ave. 3, Novosibirsk, 630090, Russia


Today the investigation of optically active paramagnetic centers in diamond is very actual

topic, since they are considered to be a promising system for quantum information processing. In

that point the most famous center is NV- center. This defect has remarkably long relaxation time

approaching one second. The other optically active centers possessing desired properties are

actively studied. Recently SiV- defect was reported to be a promising color center in diamond. It has

very sharp zero-phonon band and a weak phonon structure. Last year in the luminescence spectra of

germanium doped diamond samples a new optical center with a sharp ZPL 602 nm was detected.

Considering the new center to have Ge split-vacancy structure, the new defect was proposed to be

paramagnetic.

For this work diamonds were synthesized using a high-pressure “split-sphere” multi-anvil

apparatus in Mg-Ge-C system at 1700-1800ºC and 7 GPa. In the photoluminescence spectra of the

diamond crystals (80 K, λex=532 nm) there was an intense system 602 nm that corresponded to the

germanium-vacancy center. In the EPR spectra of the samples a new spectrum with electron spin

S=1 was detected along with substitutional nitrogen P1 centers and silicon-vacancy centers.

Investigation of the angular dependence allowed us to establish spin Hamiltonian parameters of this

center (Fig. 1): g||=2.0025(1), g=2.0027(1), D=80.3(5) mT. This center was axially symmetric with

the symmetry axis parallel to <111>. Additional growth experiments were performed with

approximately 50% enrichment of 73

Ge. HFS from one 73

Ge atom (I=9/2) with almost isotropic

A≈1.64 mT was found for the new EPR spectrum (Fig. 2).

It is known that large impurity atoms, such as silicon, nickel, etc. form the defects with a

structure of impurity atom in the semi-vacancy position with appropriate D3d symmetry. As the new

germanium-containing paramagnetic center has the same symmetry and spin state as silicon-

vacancy center SiV0 (KUL1), the new paramagnetic center is proposed to be the neutral defect with

the structure of germanium atom in the double semi-vacancy position.

1200 1220 1240 1260 1280 1300

Inte

nsity (

a. u.)

Magnetic field (mT)

GeV

SiV0H||<110>

P1

Acknowledgements: This research was supported by Russian Science Foundation under Grant No. 14-27-00054.

1280 1285 1290 1295

Magnetic field (mT)

Inte

nsity (

a. u

.)

HFS(73

Ge)H||<110>

Fig. 1. EPR spectrum of the sample at room

temperature, Н||<110>.

Fig. 2. HFS of 73

Ge around GeV line for 73

Ge

enriched sample, Н||<110>.

PO-16


111

High-frequency EPR data for Fe2+

and Cr2+

spin S = 2 ions in natural and

synthetic forsterite revisited: effective S~

= 2 vs fictitious S' = 1 approach M. Kozanecki,

1 C. Rudowicz

2,3

1Faculty of Chemistry, A. Mickiewicz University (AMU),Umultowska 89B, 61-614 Poznań, Poland,

2Visiting Professor: Faculty of Chemistry, A. Mickiewicz University, Poznań, Poland,

3On leave of absence from: Inst. of Phys., West Pomeranian Univ. of Technology Szczecin, Poland


Forsterite (Mg2SiO4) can accommodate various transition-metal 3dN ions at the distorted

octahedral Mg sites as well as tetrahedral Si sites making an important crystals for tunable solid-

state lasers [1]. The 3d6 and 3d

4 ions with spin S = 2 are important, since they exhibit large zero

field splitting (ZFS) [2] and hence require instead of usual X- or Q-band EMR techniques [3], the

novel high-magnetic field and high-frequency EMR (HMF-EMR) techniques [4,5]. In this work we

revisit the HMF-EMR data for Fe2+

and Cr2+

(S = 2) ions in natural and synthetic forsterite [6]. The

determination of the spin Hamiltonian (SH) parameters for Fe2+

[6] was based on the fictitious S' =1

approach. This hinders direct comparison of the axial (D) and rhombic (E) second-rank ZFS

parameters (ZFSPs) [2] available in literature for Fe2+

ions with the effective spin S~

= 2 [7,8]. The

wide-band EPR spectrometer covering a limited frequency region of = 65 to 850 GHz allowed for

detection of only three transitions in the temperature range of 4.2–15 K in the magnetic field (B) up

to 9.5 kG [6]. These three transitions were described in the framework of the fictitious S' = 1.

The methodology for derivation of appropriate relations to convert the ZFSPs D' and E' (S' = 1)

determined for Fe2+

in Mg2SiO4 [6] to the ZFSPs D and E ( S~

=2) available in literature for Fe2+

ions

in similar crystal structures is presented. By correlating various possible combinations of the energy

levels for the spin S' = 1 with those for the spin S~

= 2, alternative sets of conversion relations are

obtained. Subsequently, the HMF-EPR data [6] for Fe2+

in forsterite are reinterpreted. Applications

of the derived relations for other non-Kramers ions with spin S = 2 in forsterite, e.g. Cr2+

, as well as

in related ion-host systems are also considered. The numerical results indicate that the magnitudes

of the converted ZFSPs are compatible to these reported for Fe2+

(S = 2) ions in similar crystal

structures. Consideration of the 4th-rank ZFSPs existing for S~

= 2 systems [7,8,9] and their impact

on the values of the fitted 2nd-rank ZFSPs and energy levels is now in progress. The theoretical

description incorporating equations involving not only the 2nd-rank ZFSPs (D and E), but also the

corresponding 4th-rank ZFSPs 4

qB expressed in the extended Stevens operator notation [2] will be

worked out. Illustrative preliminary results of the extension to the 4th-rank ZFSPs will be discussed.

To verify which combination of the S' = 1 energy levels and the S~

= 2 ones, used to derive

conversion relations, actually applies for Fe2+

in forsterite, the ZFSPs need to be estimated by

independent methods, e.g. using the MSH/VBA program [7,8]. Calculations and data comparison

will be carried out for several compounds containing Fe2+

and Cr2+

ions.

References: 1. S. Kück, Appl. Phys. B 72 (2001) 515. 2. C. Rudowicz, M. Karbowiak, Coord. Chem. Rev. 287 (2015) 28 3. S.K. Misra, Ed., Multifrequency Electron Paramagnetic Resonance, Wiley-VCH, Weinheim, 2011 4. J. Telser, J. Krzystek, A. Ozarowski, J. Biol. Inorg. Chem. 19 (2014) 297 5. T. Sakurai, K. Fujimoto, R. Goto, S. Okubo, H. Ohta, Y. Uwatoko, J. Magn. Reson. 223 (2012) 41 6. G.S. Shakurov, T.A. Shcherbakova, V.A. Shustov, Appl. Magn. Reson. 40 (2011) 135 7. C. Rudowicz, H.W.F. Sung, Physica B 337 (2003) 204. 8. M. Zając, I. E. Lipiński, and C. Rudowicz, J. Magn. Mag. Mat. 401 (2016) 1068 9. C. Gill, P.A. Ivey, J. Phys. C: Solid State Phys. 7 (1974) 1536 Acknowledgements:

CZR acknowledges the Polish National Science Center research grant DEC-2012/04/M/ST3/ 00817; MK is grateful to

the Faculty of Chemistry, A. Mickiewicz University, for a PhD scholarship.

PO-17


112

EPR and optical Spectroscopy of transition and rare-earth ions doped systems

Ram Kripal

EPR Laboratory, Department of Physics, University of Allahabad, Allahabad, India.


Electron paramagnetic resonance (EPR) studies are reported on vanadyl (VO2+

) ions in

potassium oxalate monohydrate (POM), Cr3+

doped lithium potassium sulphate (LPS), Gd3+

ions in

ammonium hydrogen malonate (AHM) single crystals at room temperature and Mn2+

doped

tetramethylammoniumtetrachlorozincate (TMATC-Zn) single crystal at liquid nitrogen temperature

(77K). The results indicate that the paramagnetic impurity takes up an interstitial site in POM. The

angular variation of EPR spectra in three mutually perpendicular planes are used to determine the

spin Hamiltonian parameters. The optical absorption spectrum of VO2+

ions in POM is also studied

at room temperature. The analysis of the spectrum indicates that the first three bands correspond to

d–d transitions and the last band is probably charge transfer band. From optical and EPR data

various bonding parameters are obtained and nature of bonding in the crystal is discussed. Using

EPR data the site symmetry of Cr3+

ion in LPS is discussed. Cr3+

ion enters the lattice

substitutionally replacing K+ site. By correlating optical and EPR data the nature of bonding in the

crystal is discussed. Mn2+

spin Hamiltonian parameters in TMATC-Zn are evaluated employing a

large number of resonant line positions observed for various orientations of the external magnetic

field. The values of the zero field parameters that give good fit to the observed EPR spectra are

obtained. The percentage of covalency of the metal ligand bond has also been determined. From the

optical absorption study, the lattice distortion is suggested. The electron repulsion parameters (B

and C) and crystal field parameters (Dq and ) providing a good fit to the observed optical spectra

are evaluated. The considerable decrease in the values of Band C parameters from free ion values

has indicated that there exists a fair amount of covalent bonding between the central metal ion and

the ligand. On the basis of deviations g =g-2.0023 it has been ascertained whether electrons are

transferred to or from the central ion by the action of bonding. Detailed EPR analysis of Gd3+

in

AHM indicates the presence of four physically equivalent but magnetically inequivalent sites. The

zero-field splitting parameters and g factor are determined. The Gd3+

ion is in 8S state; its levels are

split by the action of the crystalline electric field of monoclinic symmetry. The optical absorption

spectra of Gd3+

ions in single crystals of ammonium hydrogen malonate are also recorded at room

temperature. The energy levels of the 4f7 configuration are calculated and compared with those

observed experimentally.

Keywords: EPR; optical absorption; spin-Hamiltonian; crystal field; covalency.

References: 1. R. Kripal and M. Maurya, Mat. Chem. Phys. 108 (2008) 257. 2. R. Kripal and V. Mishra, J. Magn. Reson. 172 (2005) 201. 3. J. A. Weil, J. R. Bolton, J. E. Wertz, Electron Paramagnetic Resonance: ElementaryTheory and Practical

Applications, Wiley, New York, 1994. 4. S. K. Misra, Chapter IX, in: C. P. Poole Jr., H. A. Farach (Eds.), Handbook of ESR,Vol.2, Springer, New York, 1999,

p. 291. 5. S. K. Misra, Physica B 203 (1994) 193. 6. S. Stoll and A. Schweiger, J. Magn. Reson. 170 (2006) 42. 7. C. Rudowicz and H. W. F. Sung, Physica B 300 (2001) 1.

Acknowledgements:

The author is thankful to the staff of SAIF, IITB, Powai, Mumbai for providing EPR facilities.

PO-18


113

Distance Measurements in Hepatitis C Virus RNA Internal Ribosome Entry Site and Human Ribosomes

Olesya A. Krumkacheva,1 Elena S. Babaylova,2 Alexey A. Malygin,2 Alexander A. Lomzov,2 Dmitrii V.

Pyshnyi,2 Matvey V. Fedin,1 Maxim M. Yulikov,3 Gunnar Jeschke,3

Galina G. Karpova2 and Elena G. Bagryanskaya4

1International Tomography Center SB RAS, Novosibirsk, Russia 2Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia

3Physical Chemistry Laboratory, ETH-Hönggerberg, Zürich, Switzerland 4N.N.Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Novosibirsk, Russia


Pulsed dipolar EPR spectroscopy is nowadays widely applied for distance measurements in

biologically-important systems. Although significant progress has been achieved in this field, a number of challenges still remain. One of them is site-directed spin labeling (SDSL) of long (exceeding 50-70 base pairs) natural nucleic acids. Recently, we developed promising approach to SDSL of RNAs, which is based on the complementary-addressed reaction between target RNA residue and a derivative of oligodeoxyribonucleotide [1]. Contrary to other methods, novel approach is generally applicable to RNAs of arbitrary size. In this work we apply this approach to SDSL of Hepatitis C Virus (HCV) RNA Internal Ribosome Entry Site (IRES) consisting of up to 350 nucleotides and having a complicated spatial structure, and thereby for the first time clearly demonstrate the SDSL of long structured RNA [2]. Double spin labeling of HCV RNA IRES allowed application of pulsed DEER and obtaining reasonable spin-spin distance distribution, which agrees well with the results of MD calculations. Thus, novel complementary-addressed SDSL approach in conjunction with EPR and MD allows structural studies of long natural RNAs with nanometer resolution and can be applied to systems of biological and biomedical significance.

We also proposed new method for pulsed dipolar EPR studying of complicated supramolecular complexes with human 40S and 80S ribosomes responsible for the protein synthesis. In our work [3] a derivative of nonaribonucleotide pUUCGUAAAA with nitroxide spin labels attached to the 5’-phosphate and to the C8 atom of the adenosine in 6th position (mRNA analogue) was used for studying such complexes using DEER spectroscopy. The results of this study are the first demonstration of DEER application for measurements of intramolecular distances in multicomponent supramolecular complexes involving intricate cellular machineries and for evaluating dynamic properties of ligands bound to these machineries.

References: 1. .S. Babaylova et al, Org. Biomol. Chem., 2014, 12(19), 3129-3136. 2. E. Babaylova et al , NAR, doi:10.1093/nar/gkw516 3. A. Malygin et al. Biophysical Journal, 2015, 109(12), 2637-2643. Acknowledgements: This work has been supported by Russian Science Foundation (no. 14-14-00922).

PO-19


113-B

Triarylmethyl Radicals: EPR Study of 13C Hyperfine Coupling Constants

Andrey Kuzhelev,1,3 Victor Tormyshev,1,3 Olga Rogozhnikova,1,3 Dmitry Trukhin,1,3

Tatiana Troitskaya,1,3 Rodion Strizhakov,1 Olesya Krumkacheva,2,3 Matvey Fedin,2,3 Elena

Bagryanskaya1,3

1N.N. Voroztsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9, Novosibirsk, 630090, Russia

2International Tomography Center SB RAS. Institutskaya ЗА, Novosibirsk, 630090, Russia 3Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia


Triarylmethyl (TAM) radicals are widely used in Electron Paramagnetic Resonance (EPR)

spectroscopy as spin labels and in EPR imaging as spin probes for in vivo oxymetry. One of the key advantages of TAMs is extremely narrow EPR line, especially in case of deuterated analogues (~5 µT). Another advantage is their slow spin relaxation even at physiological temperatures allowing, in particular, application of pulsed dipolar EPR methods for distance measurements in biomolecules [1-3].

In this work a large series of TAM radicals and their deuterated analogues is synthesized, and

corresponding spectroscopic parameters including 13C hyperfine constants are obtained for the first time. The negligible dependence of 13C hyperfine constants on solvent, as well as on structure and number of substituents at para-C atoms of aromatic rings, has been found. In addition, we have demonstrated that 13C signals at natural abundance can be employed for successful room-temperature distance measurements using Pulsed Electron Double Resonance (PELDOR or DEER) [4].

References: 1. Z. Y. Yang, Y. P. Liu, P. Borbat, J. L. Zweier, J. H. Freed, W. L. Hubbell, J. Am. Chem. Soc. 2012, 134, 9950-9952. 2. G. Y. Shevelev, O. A. Krumkacheva, A. A. Lomzov, A. A. Kuzhelev, O. Yu. Rogozhnikova, D. V. Trukhin, T. I.

Troitskaya, V. M. Tormyshev, M. V. Fedin, D. V. Pyshnyi, E. G. Bagryanskaya, J. Am. Chem. Soc. 2014, 136, 9874-9877.

3. A. A. Kuzhelev, G. Y. Shevelev, O. A. Krumkacheva, V. M. Tormyshev, D. V. Pyshnyi, M. V. Fedin, E. G. Bagryanskaya, J. Phys. Chem. Lett. 2016, 7, 2544−2548.

4. A. A. Kuzhelev, V. M. Tormyshev, O. Yu. Rogozhnikova, D. V. Trukhin, T. I. Troitskaya, R. K. Strizhakov, O. A. Krumkacheva, M. V. Fedin, E. G. Bagryanskaya, Z. Phys. Chem. 2016, in press.

Acknowledgements: This work was supported by Russian Science Foundation (no. 14-14-00922).

PO-19B


114

Study of Nitroxide Relaxation in Glassy Trehalose

for Room-Temperature Pulsed EPR Distance Measurements

Andrey Kuzhelev,1,4

Rodion Strizhakov,1 Olesya Krumkacheva,

2,4 Yuliya Polienko,

1,4 Denis Morozov,

1,4

Georgiy Shevelev,3,4

Dmitrii V. Pyshnyi,3 Igor Kirilyuk,

1,4 Matvey Fedin,

2,4 Elena Bagryanskaya

1,4

1N.N. Voroztsov Novosibirsk Institute of Organic Chemistry SB RAS, Av. Lavrentjeva 9,


3Institute of Chemical Biology and Fundamental Medicine SB RAS, Av. Lavrentjeva 8, Novosibirsk, 630090,

Russia 4Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia


Trehalose has been recently promoted as efficient immobilizer of biomolecules for room-

temperature EPR studies, including distance measurements between attached nitroxide spin labels

[1]. Generally, the structure of nitroxide influences the electron spin relaxation times, being crucial

parameters for room-temperature pulse EPR measurements. Therefore, in this work we investigated

a series of nitroxides with different substituents adjacent to NO-moiety including spirocyclohexane,

spirocyclopentane, tetraethyl and tetramethyl groups. Electron spin relaxation times (T1, Tm) of

these radicals immobilized in trehalose were measured at room temperature at X- and Q-bands

(9/34 GHz). In addition, a comparison was made with the corresponding relaxation times in

nitroxide-labeled DNA immobilized in trehalose. In all cases phase memory times Tm were close to

700 ns and did not essentially depend on structure of substituents. Comparison of temperature

dependences of Tm at T = 80–300 K shows that the benefit of spirocyclohexane substituents well-

known at medium temperatures (~100–180 K) becomes negligible at 300 K. Therefore, unless there

are specific interactions between spin labels and biomolecules, the room-temperature value of Tm in

trehalose is weakly dependent on the structure of substituents adjacent to NO-moiety of nitroxide.

The issues of specific interactions and stability of nitroxide labels in biological media might be

more important for room temperature pulsed dipolar EPR than differences in intrinsic spin

relaxation of radicals [2].

References: 1. V. Meyer, M. A. Swanson, L. J. Clouston, P. J. Boratyński, R. A. Stein, H. S. Mchaourab, A. Rajca, S. S.

Eaton, G. R. Eaton, Biophys. J. 2015, 108, 1213-1219. 2. A. A. Kuzhelev, R. K. Strizhakov, O. A. Krumkacheva, Y. F. Polienko, D. A. Morozov, G. Y. Shevelev, D. V.

Pyshnyi, I. A. Kirilyuk, M. V. Fedin, E. G. Bagryanskaya, J. Magn. Reson. 2016, 266, 1-7.

Acknowledgements:


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115

Triarylmethyl Radicals: Study of Room-Temperature Relaxation Properties at

the X- and Q- Bands

Andrey Kuzhelev,1,3

Dmitry Trukhin,1,3


Rodion Strizhakov,1

Olga Rogozhnikova,1,3

Tatiana Troitskaya,1,3

Matvey Fedin,2,3

Victor Tormyshev,1,3


1N.N. Voroztsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9,


3Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia


Triarylmethyl radicals (trityls, TAMs) represent a relatively new class of spin labels. The long

relaxation of trityls at room temperature in liquid solutions makes them a promising alternative for

traditional nitroxides. In this work we have synthesized a series of TAMs including perdeuterated

Finland trityl (D36 form), mono-, di-, and triester derivatives of Finland-D36 trityl, the deuterated

form of OX63, the dodeca-nbutyl homologue of Finland trityl, and triamide derivatives of Finland

trityl with primary and secondary amines attached. We have studied room-temperature relaxation

properties of these TAMs in liquids using pulsed electron paramagnetic resonance (EPR) at two

microwave frequency bands. We have found the clear dependence of phase memory time (Tm ∼ T2)

on the magnetic field: room-temperature Tm values are ∼1.5−2.5 times smaller at the Q-band (34

GHz, 1.2 T) than at the X-band (9 GHz, 0.3 T). This trend is ascribed to the contribution from g-

anisotropy that is negligible at lower magnetic fields but comes into play at the Q-band. In

agreement with this, the difference between T1 and Tm becomes more pronounced at the Q-band

than at the X-band due to increased contributions from incomplete motional averaging of g-

anisotropy. Linear dependence of (1/Tm − 1/T1) on viscosity implies that g-anisotropy is modulated

by rotational motion of the trityl radical. On the basis of the analysis of previous data and results of

the present work, we conclude that, in the general situation where the spin label is at least partly

mobile, the X-band is most suitable for application of trityls for room-temperature pulsed EPR

distance measurements [1].

References: 1. A. A. Kuzhelev, D. V. Trukhin, O. A. Krumkacheva, R. K. Strizhakov, O. Y. Rogozhnikova, T. I. Troitskaya, M. V.

Fedin, V. M. Tormyshev, E. G. Bagryanskaya, J. Phys. Chem. B 2015, 119, 13630-13640.

Acknowledgements:


PO-21



116

Photosensitive NO-releasing Ruthenium Complexes

Minyeong Kim and Hong-In Lee

Department of Chemistry, Kyungpook National University, Daegu, Republic of Korea


Since the discovery of Nitric Oxide (NO) as one of the major signal-transduction molecules in

cells, there have been many attempts to devise acute NO-delivering systems for the purpose of

developing disease therapies as well as studying cell functions. Metal-nitrosyl complexes are often

releasing NO by light activation. This ability can be adapted to killing cancer cells with high

specificity because high concentration of NO in cells induces apoptosis. Ru-NO complexes have

been studied for the usages of these photodynamic therapy (PDT) agents for a time.

This research aims at developing Ru-NO complexes which absorb long wavelength visible light

to release NO with high quantum yield. Previously, we have developed a new Ru-NO bis-

pyridyl/biscarboxamide compound, [Ru(III)(ebpp)(Cl)(NO)], where H2ebpp = N,N’-(ethylene di-p-

phenylene)bis(pyridine-2-carboxamide), to be tested as a model NO-releasing agent. Here, we

present the strategies to develop visible-light sensitive NO-releasing Ru complexes with higher

quantum yield. We introduce new series of ligands, salophen and naphophen, to develop Ru-NO

complexes. In this poster, we present UV-VIS and EPR data which can be interpreted as that the

diamagnetic [Ru-NO]6 electronic state of the complex becomes low-spin Ru(III) (d

5, S=1/2) state

upon losing NO by photoactivation.

PO-22


117

EPR line widths of magnetically concentrated rare-earth compounds: a

theoretical calculation for crystal with low symmetry

Hong-Gang Liu and Wen-Chen Zheng

Department of Materials Science, Sichuan University, Chengdu 610064, P. R. China


The electron paramagnetic resonance (EPR) line widths of magnetically concentrated rare-earth

compounds such as double alkali-rare-earth molybdates and tungstates are generally broader than

their magnetically diluted counterparts. Such broadening of EPR lines are mainly ascribed to the

contribution of spin-spin interactions between lanthanide ions in these crystals and their

microscopic origins have been theoretically investigated by van Vleck and Anderson’s pioneering

works. In the present study, the calculation formulas for EPR line widths of magnetically

concentrated rare-earth compounds with cubic symmetry have been generalized by us to the crystals

with lattice of lower symmetry. Both exchange and dipole-dipole interactions between lanthanide

ions are considered in the calculations. With the help of the derived formulas, the experimental EPR

line widths of KYb(MoO4)2 and KYb(WO4)2 crystals are reasonably explained and the anisotropic

exchange interaction parameters (Jxx, Jyy, Jzz) for such two magnetically concentrated systems are

also derived by our theoretical consideration.

References: 1. Van Vleck J. H., The dipolar broadening of magnetic resonance lines in crystals, Phys. Rev. 1948, 74, 1168-1183. 2. Anderson P. W., Exchange narrowing in paramagnetic resonance, Rev. Mod. Phys. 1953, 25, 269-276. 3. Pujol M. C., Aguilo M., Diaz F., Borowiec M. T., Prokhorov A. D., Dyakonov V. P., Nabialek A., Piechota S. and

Szymczak H., Electron paramagnetic resonance studies in KYb(WO4)2, Physica B 2007, 388, 257-260. 4. Kobets M. I., Khats’ko E. N., Dergachev K. G. and Kalinin P. S., Electronic paramagnetic resonance of rare-earth

ions Yb3+

, Pr3+

, Dy3+

, and Nd3+

in double molybdates and tungstenates, Low Temp. Phys. 2010, 36, 611-617. 5. Krygin I. M., Prokhorov A. D., Dyakonov V. P., Borowiec M. T. and Szymczak H., Spin-spin interaction and the

EPR spectrum of KDy(WO4)2, Phys. Solid State 2003, 45, 2083-2092. 6. Liu H. G. and Zheng W. C., Theoretical investigations of the optical spectra and EPR parameters for the isolated and

pairs of trivalent ytterbium ions in Li6Y(BO3)3 crystal, Opt. Mater. 2015, 49, 337-342.

Acknowledgements: This work was financially supported by the National Natural Science Foundation of China (Grant No. 11404229).

PO-23



118

The Absorption Tendency of Mugieic Acid on Soil Mineral in

Amagatsuji Area, Nara

Yuki Matsuoka

Faculty Department of physics Nara Women's University, Kitauoyanishi-machi Nara 630-8506, Japan


Graminaceous plants secrete mugieic acid from their root to uptake iron that is essential for

their growth. The mugineic acid is an iron-chelating phytosiderophone.[1] The uptake process of

iron as Fe3+

is well studied from a point of biological view, but the effects of the mugineic acid on

soil mineral from a point of physical or crystallographical view was not reported. It is useful to get

information about the tendency of iron uptake for each iron-containing mineral. The information

makes us easy to match of the nature of the soil and the characteristic of graminaceous plants. And

then it will prevent graminaceous plants from suffering from iron-deficiency and allow us to

cultivate them in less fertilizer.

To study preferred mineral for iron uptake about rice plants, we measured paddy soil and clay

with X-ray diffraction measurements and EPR. Samplings area is Amagatsuji, Nara. Sample soils

were collected at neighboring of rice plant root and at the paddy ridge as a comparison sample. The

cultivar of rice plant in the paddy field is Yamadanishiki.

The samples were divided into clay and soil minerals. Furthermore the clay samples were

divided into five kinds by the sunk depth. The soil samples were sieved and divided into four

particle size, and finally separated to three groups by their specific gravity.

As iron-including mineral, biotite and chlorite were observed in the clay samples, and ilmenite,

hornblend and biotite were observed in the soil samples. Signals of Fe3+

were observed both in clay

and soil samples. Signals of g = 2, g = 4.1 and weak g = 6 were observed in all clay samples. The

intensity of g = 2 was stronger at paddy ridge than that of root-neighboring.

In soil samples, g = 9, weak g = 2 and plural signals around g = 3 ~ 9 were observed only in

heaviest gourp of specific gravity d > 2.7. Weak g = 2 and some of plural signals around g = 6

originate from hornblend. The g = 9 signal that is supposed to originate from iluminate has higher

intensity at paddy ridge than root-neighboring in soil sample. And smaller diameter sample shows

more weak signal intensity. We conclude that Yamadanishiki in Amagatsuji area uptakes Fe3+

mainly from iluminate.

References: 1. S. Takagi Soil Sci, Plant Nutr., 1976, 22, 423

PO-24


119

PELDOR Analysis of Biradical Conformations Basing on Monte Carlo Solution

of the Reverse Problem

Anna Matveeva, Sergei Dzuba

Voevodsky Institute of Chemical Kinetics and Combustion, Novosibirsk. 630090, Russia and

Novosibirsk State University, Novosibirsk. 630090, Russia


The PELDOR signal time traces contain information on the distance distribution function between two spin labels

attached to selected positions of a molecule. Thus, it becomes possible to analyze conformations of

the molecule. The analysis is based on solution of an ill-posed reverse problem. So it requires

regularization algorithms.

Several approaches to do that exist to date. The Tikhonov regularization algorithm used in well-

known DeerAnalysis [1] imposes restrictions on the smoothness of the solution. However in the

case of distributions containing both narrow and broad peaks, the algorithm smoothes out the

narrow peak. In that case, the problem can be solved in DeerAnalysis using another approach with a

priori assumption of a Gaussian nature of both peak, but the algorithm is limited to two Gaussians,

and has a tendency to slide into local minima.

In this work, we use regularization based on approximation of the solution by several

Gaussians with varying positions, widths and amplitudes. The general idea is to restrict the solution

to number of Gaussians providing good agreement with experimental data. For searching the best-

fitted result, Monte Carlo process is employed. The algorithm is implemented on a series of flexible

biradicals [2]. It is found that using only three Gaussians is enough for good agreement with

experiment.

To get solution, the program performs 106 – 10

7 trials which takes ~ 1 min. Comparison of the results obtained

by different methods shows that the proposed approach gives the best agreement with the experiment.

References:

1. G. Jeschke, V. Chechik, P. Ionita, A. Godt, H. Zimmermann, J. Banham, C. R. Timmel, D. Hilger, H. Jung, Appl. Magn. Reson. 2006, 30, 473– 498.

2. A.G. Matveeva, Yu.V. Yushkova, S.V. Morozov, I.A. Grygor’ev, S.A. Dzuba, Zeitshrift fuer Physikalische Chemi, 2016, submitted.

Acknowledgements:

This work was supported by the Russian Science Foundation, project 15-15-00021.

PO-25



120

Skin surface imaging of psoriasis vulgaris investigated by X-band EPR

Kouichi Nakagawa,1 Satoko Minakawa,

2 Daisuke Sawamura,

2 Hideyuki Hara

3

1Department of Radiological Life Sciences, Graduate School of Health Sciences, Hirosaki University, 66-1

Hon-cho, Hirosaki 036-8564, Japan 2 Department of Dermatology, Graduate School of Medicine, Hirosaki University, Hirosaki, 036-8562 Japan

3 Bruker BioSpin K. K., 3-9, Moriya-cho, Kanagawa-ku, Yokohama 221-0022, Japan


We Electron paramagnetic resonance (EPR) is useful for elucidating structural aspects of

stratum corneum (SC) [12]. Non-invasive spectroscopic characterization of the outermost layer of

the SC is an important subject in dermatology and cosmetology.

In this study, we investigated identification and locations of abnormality of the SC in patients

with psoriasis vulgaris (PV) by using 9 GHz EPR imaging.

The 9 GHz EPR spin-probe imaging of PV-SC samples

provided a useful image concerning the status of the SC. The

Hirosaki University Internal Review Board approved all

protocols used in this study.

Figure 1 shows that the strong red signal is due to probe

penetration into the PV skin. No red lesion region was

observed in the control. The EPR images showed various

sizes and number distribution concerning the disordered states

in the SC. Thus, 9 GHz EPR imaging can be useful for

detecting and identifying the location of abnormality of the

SC states. In addition, EPR imaging can potentially offer

further quantitative insights into skin-lipid states [3].

References: 1. Nakagawa K., Minakawa S., Sawamura D., J Dermatol Sci, 2013, 65, 222-223. 2. Nakagawa K., Spectrochim Acta Part A, Mol Biomol Spec, 2015, 150, 61-464. 3. Nakagawa K., Minakawa S., Sawamura D., Hara H., J Dermatol Sci, 2016, 81,71-73.

Acknowledgements: Part of this research was supported by a Grant-in-Aid for Challenging Exploratory Research (15K12499) and for

Scientific Research (B) (25282124) from the Japan Society for the Promotion of Science (JSPS) (K.N.).

Figure 1. The image shows the psoriasis

vulgaris (PV) (top) and control (bottom)

samples. The aqueous solution of the spin

probe, 5-doxylstearic acid (5-DSA) was

used.

Dis

tance [m

m]

Distance [mm] 3 mm

PV

Control

PO-26


121


Egor A. Nasibulov,1,2

Alexey S. Kiryutin,1,2

Alexandra V. Yurkovskaya,1,2

Hans-Martin Vieth1,3

and Konstantin L. Ivanov1,2

1International Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3A,

Novosibirsk, 630090, Russia 2Novosibirsk State University, Pirogova str. 2, Novosibirsk, 630090, Russia

3Freie Universität Berlin, Arnimallee 14, Berlin, 14195, Germany


DNP is a powerful method to create non-thermal polarization of nuclear spins, thereby

enhancing their NMR signals. The DNP effect is due to transfer of the electron spin polarization to

nuclear spins in the presence of MW-pumping; the NMR enhancement is proportional to the ratio of

the magnetogyric ratios of electron 𝛾𝑒 and nucleus 𝛾𝑛. In the case of Overhauser-type DNP (DNP in

liquids) the NMR signal enhancement is

𝜀 = 1 + 𝜉 ⋅ 𝑓 ⋅ 𝑠 ⋅𝛾𝑒

𝛾𝑛 (1)

with 𝜉, 𝑓 and 𝑠 being the coupling factor, leakage factor and saturation factor, respectively. It is

well-known that MW-pumping, required for reaching maximal 𝑠 values, can cause substantial

heating of the sample. For this reason, using pulsed techniques of pumping instead of cw-pumping

is of great interest [1].

Here Overhauser-type DNP formed by a periodic sequence of EPR-pulses is discussed. Earlier

[2] the case of a single ideal pulse per period was discussed and an elegant general expression for

the NMR enhancement has been obtained. The expression for the enhancement was shown to be

similar to that known for cw-pumping with the saturation factor re-defined as the deviation of the

electron spin magnetization from its equilibrium value averaged over the cycle of the pulse

sequence.

In this work a general theoretical approach to pulsed Overhauser-type DNP is presented. Our

theory can treat pulsed irradiation of EPR transitions for an arbitrary periodic pulse sequence. The

NMR enhancement is analyzed in detail as a function of the EPR-pulse length for ideal pulses and

pulses with a finite rise-time. It is shown that one can achieve the maximal theoretically allowed

NMR enhancement for pulsed pumping even when the duty cycle of pumping is low. Characteristic

oscillations of the DNP enhancement are found when the pulse length is stepwise increased,

originating from the coherent motion of the electron spins driven by the pulses. The dependence of

the DNP effect on the duty cycle, pulse length and electron spin relaxation times has been studied in

detail. Once the lines in the EPR spectrum are inhomogeneously broadened, higher DNP effects are expected in the

pulsed pumping mode than in the cw-mode for the same total power of microwave irradiation. Experimental low-field

DNP data are in good agreement with this theoretical approach.

References:

1. M. Alecci, D.J. Lurie, J. Magn. Reson. 1999, 138, 313-319. 2. E.A. Nasibulov, K.L. Ivanov, A.V. Yurkovskaya and H.-M. Vieth, Phys. Chem. Chem. Phys., 2012, 14, 6459-6468.

Acknowledgements:

This work has been supported by the Russian Foundation for Basic Research (projects No. 16-33-00590, 14-03-00397).

PO-27


122

Force-detected ESR measurements in a terahertz range up to 0.4 THz

T. Okamoto,1 H. Takahashi,

2 E. Ohmichi

1 and H. Ohta

3


2Organization of Advanced and Integrated Research, Kobe University, Kobe 657-8501, Japan



High-frequency ESR (HFESR) technique is very useful to understand microscopic properties of

spin systems. HFESR has advantages such as high g-value resolution and direct observation of

zero-field splitting. Multi-frequency ESR experiments also give us more detailed information of

spin systems from the view point of spectroscopic study. However, because of the lack of intense

light sources, spin sensitivity of transmission-type HFESR apparatuses is very low.

To solve this problem, we have developed a cantilever-detected HFESR technique. In this

technique, a tiny sample is mounted on a microcantilever end, and an electromagnetic wave is

irradiated onto the sample using an oversized waveguide. When ESR absorption occurs, the

corresponding magnetization change is detected as a field-gradient force acting on the sample. So

far, ESR detection at 150 GHz was achieved for a sample weighing 1 g using fiber-optic Fabry-

Perot displacement sensor [1, 2].

In this study, we successfully extended the frequency region of our force-detected ESR

technique to a terahertz range up to 0.4 THz, and achieved a spin sensitivity as high as 109

spins/Gauss in the THz range. To this end, the gradient field was substantially enhanced with use of

a dysprosium rod. The estimated field gradient was 1000 - 2000 T/m at the sample position, which

was ten times greater than that of a hollow cylindrical ferrite bead used in the previous setup. We

also used a softer cantilever for sensitive detection of ESR-induced field-gradient force.

We applied our new system to metalloporphyrin in this study. Metalloporphyrin is a model

substance of hemoproteins such as hemoglobin, and the molecular structure is similar to the

functional part of such hemoproteins. The high spin concentration of metalloporpyrin is suitable for

ESR detection and spin sensitivity evaluation. We used Gunn oscillators and backward wave

oscillators for millimeter and terahertz generation. ESR measurements were carried out at 4. 2 K.

For tetraphenylporphyrin copper (Cu-TPP), we observed single peak absorption in a broad

frequency range from 80 - 388 GHz. An analysis taking the gradient field into account gave

g=2.107, consistent with previous reports. As a next step, we focused on oxygen storage

metalloprotein, myoglobin, since its electronic structure still remains to be determined due to the

zero-field splitting. For this purpose, single crystals of myoglobin were recently grown in our

group, and ESR measurement is now undertaken. In the presentation, we will report more details of

our apparatus and ESR results obtained in the THz range.

References: 1. Y. Tokuda et al., “Development of high-sensitivity cantilever-detected ESR measurement using a fiber-optic

interferometer”, J. Magnetics 18 (2013) 173-177. 2. E. Ohmichi et al., “Multi-frequency force-detected electron spin resonance in the millimeter-wave region up to 150

GHz”, submitted. Acknowledgements:

This research was partly supported by Grants-in-Aid for Scientific Research (B) (No. 22340101 and 26287081)

and by a Grant-in-Aid for Challenging Exploratory Research (No. 26610104) from JSPS, and by the Canon

Foundation.

PO-28


123

Terahertz ESR Measurements

Susumu Okubo,1,2

So Kubota,2 Yoko Kitahara,

2 Shigeo Hara,

3 Takahiro Sakurai,

3 Hitoshi Ohta,

1,2

Daichi Yoshizawa,4 Masayuki Hagiwara,

4 Fumiko Kimura,

5 Tsunehisa Kimura,

5 Kazuhiro Nawa,

6

Yoshihiko Okamoto,7 Zenji Hiroi

8



3Center for Support to Research and Education Activities, Kobe University, Kobe 657-8501, Japan

4Center for Advanced High Magnetic Field Science, Graduate School of Science, Osaka University, Osaka

560-0043, Japan 5Devision of Forest and Biomaterials Science, Kyoto University, Kyoto 606-8502, Japan

6Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan

7Department of Applied Physics, Nagoya University, Nagoya 464-8603, Japan

8Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan


Recently, low-dimensional frustrated spin system have attracted much attention to have novel

ground states. The existence of a spin nematic phases, analogous to nematic liquid crystal, is

expected theoretically in S=1/2 ferromagnetic and antiferromagnetic frustrated chain at slightly

below the saturation field [1]. Previous candidate S=1/2 frustrated J1-J2, LiCuVO4 has verification

problems of higher saturation field (~44T) and random substitution of Li ion [2]. New candidate

substance NaCuMoO4(OH) shows relatively low saturation field of 25 T and no random substitution

[3]. Superexchange interactions are estimated to be J1=-51 K and J2=36 K from the magnetic

susceptibility measurements [3]. The specific heat does not show long range order down to 0.6 K.

Furthermore, relaxation time from NMR measurements behave a spin density wave (SDW), which

is expected blow the spin nematic phase. Previously, in order to investigate a spin nematic phase,

high-field ESR measurements of NaCuMoO4(OH) powder sample have been performed. However,

feature of a spin nematic phase could not observe due to powder sample. In this work, we treat a

three-dimensional magnetically aligned powder sample as quasi large single crystal [4]. Terahertz

ESR measurements of NaCuMoO4(OH) have been performed at 1.8 K using the pulsed magnetic

field up to 50 T. Gunn Oscillator, BWO and FIR laser are used as light sources in the frequency

range from 60 GHz to 1.5 THz [5]. Field dependence of resonance field and linewidth at spin

nematic phase will be discussed.

References:

1. T. Hikihara, L. Kecke, T. Momoi, A. Furusaki, Phys. Rev. B, 2008, 78 , 144404-19. 2. N. Buttgen, K. Nawa, T. Fujita, M. Hagiwara, P. Kuhns, A. Prokofiev, A. P. Reyes, L. E. Svistov, K. Yoshimura, M.

Takigawa, Phys. Rev. B, 2014, 90, 134401-7. 3. K. Nawa, Y. Okamoto, A. Matsuo, K. Kindo, Y. Kitahara, S. Yoshida, S. Ikeda, S. Hara, T. Sakurai, S. Okubo, H.

Ohta, Z. Hiroi, J. Phys. Soc. Jpn., 2014, 83, 103702-5. 4. F. Kimura, C. Chang, F. Kimura, M. Maeyama, Appl. Crystallogr., 2009, 42, 535-537. 5. S. Okubo, H. Ohta, Y. Inagaki, T. Sakurai, Physica B, 2004, 246-247, 627-632.

Acknowledgements

This work was carried out by the joint research in the ISSP, the Univ. of Tokyo and KOFUC network of western Japan

pulsed high magnetic field COE.

PO-29


124

Investigation of guest−host interaction under gas sorption in the

Zn2-x(Cu)x(bdc)2(DABCO) with EPR spectroscopy

Artem Poryvaev,1,2

Alena Sheveleva,1,2

Danil Dybtsev,3 Pavel Demakov,

2,3 Matvey Fedin

1,2



3N.N. Nikolaev Institute of Inorganic Chemistry SB RAS, Lavrentiev av. 3, 630090, Novosibirsk, Russia


Metal−organic frameworks (MOFs) represent a new class of porous crystals, which has

attracted chemist and material scientists worldwide due to their extraordinary physicochemical and

mechanical properties and potential applications in energy and biomedicine fields. One of the

applications of MOFs are adsorptive separation and gas storage which are very important in

industry. Generally, for this purposes solid materials such as zeolites, activated carbons, or silica

gels are used as adsorbents. With an ever increasing need for a more efficient, energy-saving, and

environmentally benign process must be found.

Zn2(bdc)2(DABCO) have a potential application for hydrogen, carbon dioxide and hydrocarbon

storage. For investigation this MOF using EPR spectroscopy our colleagues was synthesized

magnetically diluted Zn2-xCux(bdc)2(DABCO), where Zn/Cu ratio equal 1000.

In this work we study interaction Zn2-xCux(bdc)2(DABCO) with H2, CO2 and cyclohexane

using pulse EPR spectroscopy. We also present data on relaxation parameters of Cu sites interacting

with molecules of this compound.

Acknowledgements

We are grateful to the Russian Science Foundation (no. 14-13-00826) for financial support.

PO-30


125

Magnetic properties of Cu1.8Mn1.2BO5 crystal

Rushana M. Eremina,1,2

Ivan V. Yatsyk,1,2

Evgeniya M. Moshkina,3 Mikhail V. Rautskii,

3 Leonard N.

Bezmaternykh,3 Hans-Albrecht Krug von Nidda,

4 Alois Liodl

4

1Kazan E. K. Zavoisky Physical-Technical Institute of the RAS, Sibirsky tract 10/7, Kazan, 420029, Russia

2Kazan (Volga Region) Federal University, Kremlyovskaya st. 18, 420018, Kazan, Russia

3 L .V. Kirensky Institute of Physics, 660036 Krasnoyarsk, Russia

4Institut fur Physik, University Augsburg, 86135 Augsburg, Germany


Cu1.8Mn1.2BO5 single crystals were synthesized by the flux method with the ratio of the initial

components Bi2Mo3O12: 1.3B2O3: 0.7Na2CO3: 0.7Mn2O3: 2.1CuO. The grown single crystals have

the form of orthogonal prisms with a length of 10 mm and a transverse size of about 2 mm. The

sample belongs to the space group P21/c. The magnetization measurements showed that the phase

transition temperature in Cu1.8Mn1.2BO5 is T~90K. In the 75 K region, a feature in the magnetic

susceptibility behavior is observed in both ZFC and FC regimes, which can be related to different

temperature dependence of magnetization of different sublattices Mn and Cu. ESR measurements

were carried out in the paramagnetic regime at the temperature above the phase transition

temperature T~90K at the 9.48GHz (X-band) and 34GHz (Q-band). In this temperature range the

ESR spectrum of Cu1.8Mn1.2BO5 consists of one broad exchange-narrowed resonance line. Near the

phase transition the ESR linewidth exhibits its minimum value of about 1500 Oe in X- band and

2500 Oe in Q-band (Fig.1). Above the phase transition the linewidth increases monotonically with

increasing temperature. In addition, the linewidth shows a pronounced anisotropy which depended

from frequency band. The g-factor of the resonance signal are anisotropy and equal along one

direction g1=1.81 and along second direction g2=1.92.

60 80 100 120 140 160 180 200 220 240 260 280

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

5500

6000

Cu1.8

Mn1.2

BO5

(

Oe)

T (K)

X-band

X-band

Q-band

Q-band

Fig. 1. Temperature dependence of ESR linewidth in X- and Q- band in two directions of magnetic fields.

Acknowledgements

This work was supported by the RFBR no 16-32-50083

PO-31


126

Continuous Wave and Pulse EPR study of gas sorption in ZIF-8

A.M. Sheveleva,1,2

A.S. Poryvaev,1,2

M.V. Fedin1,2




Among all verity of MOFs the most applicable seems are that which combine high

hydrothermal stability and adsorption characteristics. Due to exceptional thermal and chemical

stability, the MOF subgroup of zeolitic imidazolate frameworks (ZIFs) is of particular interest. ZIF-

8 represents both this qualities internal surface of and stability till 500oC. These make this material

one of the most attractive for researchers. In the large ZIF family, ZIF-8 is one of the most studied

ZIFs featuring a cubic lattice and sodalite (SOD) topology that contains cavities with a diameter of

11.6 Å connected via 6-ring apertures with a 3.4 Å window and 4-ring apertures. The narrow pore

windows of ZIF-8 are expected to be able to sieve branched alkanes from linear alkanes.

Recently, it was shown that ZIF-8 membranes are highly attractive for separating hydrocarbon

mixtures, such as H2/CH4, CO2/CH4, C2/C3, ethylene/ethane, propylene/propane, H2/ propane.

Therefore investigation of process of gas interaction with MOF structure has a great importance for

further development of gas storage and purification area. Adsorption studies of various gases (e.g.,

CO2, CH4 and N2) in ZIF-8 have been documented both experimentally and theoretically. Basically

by measuring and calculation of isotherm sorption curve for different gases. For more detailed

investigation of gases in such systems some other methods are needed.

In this work we have tried experimental approach for detection of gas behavior inside the MOF

by EPR of spin probe. As a probe TEMPO molecule was used. CW and Pulse EPR techniques were

applied for TEMPO@ZIF-8 system loaded with different gases. Molecular dynamic calculations

were made for qualitative explanation of experimental results.

Acknowledgements

We are grateful to the Russian Foundation for Basic Research (№ 14-03-00224) and the RF President's Grant

(MD-276.2014.3) for financial support.

PO-32


127

Electrochemical oxidation, reduction and radical anions of 2-substituted

thioxanthone-9-ones, their S-oxide derivatives and thioxanthenetrions

L.A. Shundrin, I.G. Irtegova, V.A. Loskutov, N.V. Vasilieva

N. N. Vorozhtsov Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences,

Academician Lavrent’ev Avenue, 9 , 630090 Novosibirsk, Russian Federation


Thioxanthe-9-ones and their derivatives are of interest as initiators of polymerization1 and used

as photoactivators to remove trityl protecting group during oligonucleotide synthesis2. They possess

anticancer activity also3 and are capable to reversible one-electron transfer in liquids to form long-

lived radical anions (RA).

Electrochemical reduction (ECR) of 2-substituted thioxanthen-9-ones (1) (R=Me, Cl, F, CO-

iPr) in acetonitrile (MeCN) is one-electron process with the formation of long-lived radical anions

(RA), in which the thioxanthen-9-on fragment is planar according to (U)B3LYP/6-31+G*

calculations and EPR spectroscopy data. ECR of 2-methylthioxanthene-9-on sulfoxide (2) and the

corresponding sulfone (3) represent EEC and EE-processes, respectively, their RA are not planar

and have the electron system of the pseudo -type.

Electrochemical oxidation (ECO) of (1) in MeCN is characterized by irreversible four-electron

(for 1) or two-electron (for 2) processes with the consecutive oxidation of sulfur atom. Sulfone 3 is

not oxidized in the potential sweep range 0.0<E<2.5 V. (vs. saturated calomel electrode).

Mechanisms of electrode processes were studied using simulations of the corresponding cyclic

voltammograms (CV)4.

S

O

CH3(R)

S

O

CH3

O O

S

O

CH3

O1 2 3

1 2 3

222- 332-

1+e-

-e-

+e-+e-

-e--e-

+e-+e-

-e- -e-

-2e-, +H2O -2e-, +H2O

-2H+-2H+

4, 5 RA4, 5 DA 4, 5+e

-e

+e

-e

S

OO

O

S

O O

O4 5

ECR of benzo[b]thioxanthene-6,11,12-trione (4) and the thioxanthene-1,4,9-trione (5) in

DMSO, MeCN and GMFTA is an EE-process that is characterized by two well-separated one-

electron reversible peaks in the corresponding CVs. The first peak retains reversibility in DMSO-

H2O mixtures for both compounds. Extrapolated potentials of the first ECR peaks of 4, 5 in water

were found to be 0.22 V and +0.04, respectively5. The reversibility of the first one-electron stage

of the ECR of 4, 5 together with the low peak potentials open the possibility to use 4, 5 as redox-

active labels in electrochemical DNA-sensors.

References: 1. X. Jiang and J. Yin, Macromol. Rapid Commun., 2004, 25, 748. 2. A.N. Sinyakov, A.A. Ryabinin, G.A. Maksakova, V.V. Shelkovnikov, V.A. Loskutov, E.V. Vasil’ev, N.V.

Shekleina. Russian J. Bioorg. Chem., 2010, 36, 130-132. 3. V. K. Tandon, R. V. Singh and D. B. Yadav, Bioorg. Med. Chem. Lett., 2004, 14, 2901. 4. N. V. Vasilieva, I. G. Irtegova, V. A. Loskutov and L. A. Shundrin. Mendeleev Communications. 2013, 23, 334-336. 5. N.V. Vasilieva, I.G. Irtegova, V.A. Loskutov, L.A. Shundrin. Mendeleev Communications, 2012, 22, N2, p. 111-113.

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Characterization of pure and manganese doped TiO2 nanoparticles

Ram Kripal, Vini Singh

Department of Physics, University of Allahabad, Allahabad, 211012, India


TiO2 represents an effective photocatalyst for water and air purification and for self-cleaning

surfaces. Additionally, it can be used as antibacterial agent because of strong oxidation activity and

superhydrophilicity. In the present investigation, we have synthesized pure TiO2 and Mn2+

doped

TiO2 nanoparticles using sol-gel method. The prepared materials were characterized by X-ray

diffraction (XRD) analysis, Fourier transform infra-red (FTIR) spectroscopy, ultraviolet-visible

(UV-VIS) absorption spectroscopy and Photoluminescence (PL) spectroscopy. The products were

found to be transparent in the entire visible region with cut-off wavelength within the UV region

confirming its suitability for device fabrication. Doped TiO2 were found to have higher band gap

than pure TiO2. PL spectra for doped TiO2 was shifted towards lower wavelength with increased

intensity of emission which indicates that morphology could make impacts on the intensity of

luminescence.

Keywords : Nanoparticles, XRD, FTIR, UV/Visible, PL.

References: 1. C.N.R. Rao, B. Raveau, Transition Metal Oxides, VCH, New York, 1995. 2. B.O. Regan, M. Gratzel, Nature 353 (1991) 737. 3. A. Hagfeldt, M. Gratzel, Acc. Chem. Res. 33 (2000) 269. 4. M.R. Hoffmann, S.T. Martin, W. Choi, D.W. Bahnemann, Chem. Rev. 95 (1995) 69. 5. S.Y. Huang, L. Kavan, I. Exnar, M. Gratzel, J. Electrochem. Soc. 142 (1995) L142. 6. C.J. Brinker, G.W. Scherer, Sol–Gel Science, Academic Press, San Diego, 1990. 7. E. Matijevic, Chem. Mater. 5 (1993) 412. 8. J. Tang, F. Redl, Y. Zhu, T. Siegrist, L.E. Brus, M.L. Steigerwald, Nano Lett. 5 (2005) 543–548. 9. J.F. McGilp, Surf. Rev. Lett. 6 (1999) 529. 10. T.F. Heinz, H.E. Ponath, G.I. Stegeman, Nonlinear Surface Electromagnetic Phenomena, Elsevier-Amsterdam,

1991, p. 353. 11. Y.R. Shen, The Principles of Nonlinear Optics, Wiley-Interscience, New York, 1984 (Chapter 25). 12. Y.R. Shen, J. Vac. Sci. Technol. B 3 (1985) 1464. 13. C. Yamada, T. Kimura, Phys. Rev. Lett. 70 (1993) 2344. 14. C. Yamada, T. Kimura, Phys. Rev. B 49 (1994) 14372. 15. D.J. Bottomley, G. Lupke, J.G. Mihaychuk, H.M. Van Driel, J. Appl. Phys. 74 (1993) 6072. 16. V.N. Gridnev, V.V. Pavlov, R.V. Pisarev, A. Kirilyuk, T. Rasing, Phys. Rev. B 6

Acknowledgements:

The author, Vini Singh is thankful to the Head, Department of Physics and Dr. Vikas Barnwal, Nanophosphor

Application Centre University of Allahabad, Allahabad, India, for providing departmental facilities. The author is

also thankful to U.G.C for providing Research Fellowship.

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Peptides on the Surface. The Multi-Conformity of Trichogin GA IV and

Ampullosporin A on the Silica Nanoparticles by Pulse and CW EPR

Victoria Syryamina,1,2

Rimma Samoilova,1 Yuri Tsvetkov,

1 Fernando Formaggio,

3 Sergey Dzuba

1,2

1Voevodsky Institute of Chemical Kinetics and Combustion, Institutskay Str.3, Novosibirsk, 630090, Russia

2Novosibirsk State University, Pirogova Str. 2, Novosibirsk, 630090, Russia

3Department of Chemical Sciences, University of Padova, 35131 Padua, Italy


The new class of medicine drugs is peptaibols that shows a therapeutic effect against bacteria

and fungi. The molecular mechanism of its activity relies on the membrane functioning

modification due to channel formation and/or membrane homogenization. The targeting drug

delivery that is performed by using liposomes, detergents or nanoparticles, may significantly

decreases the toxicity and side effects. Besides that, organic and inorganic nanoscale surfaces with

absorbed bioactive molecules are in interest of medical applications (prosthesis), therefore, the

intensive studies mostly by NMR and circular dichroism are performed with different peptides and

surfaces. EPR methods are also suitable for studying peptide conformation (that primary relates

with biological activity), self-association and delivery efficiency as in model system, so in

biological systems such as bacteria.

In this work the inorganic SiO2 spheres of 20 nm diameter was used for studying the

conformation changing of the short-sequence length Trichogin GA IV and medium-length

Ampullosporin A. The non-aggregated peptide was placed to the silica surface from different polar

solvents – methanol and methylene chloride. The SiO2 shows a high capacity: it absorbs almost

peptide from the solvent, that forms clusters on the silica surface. The fractal dimension of inter-

molecular interaction changes from solvent value d/3=1 to surface value ~ 0.7. Beside that, the

intra-molecular state changes with transition from solvent to surface: the absorbed peptide

secondary structure is more elongated and shows poly-conformism. However, after “washing-out”

from the silica surface, peptides return to its primary structure. The spin-probe degradation solvent

effect was observed: the delivery from methylene chloride decreases the ratio of double-labeled

molecules after washing from SiO2 to 0.75, while the methanol almost saves the biradical.

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Dynamic Electron Polarization Created by the Interaction between Singlet

Oxygen and Trityl Radical

Hirona Takahashi,1 Toshiro Tamura,

1 Mai Kato,

1 Valery Khramtsov,

2 Akio Kawai

1

1Tokyo Institute Technology, Tokyo, Japan

2West Virginia University, Morgantown, USA


Singlet oxygen O2(1Δg) is categorized to activated oxygen species. Its importance is widely

recognized in many research fields, and its reactivity under various environments has been studied

by various spectroscopic methods. According to our previous studies, dynamic electron polarization

(DEP) is created by the quenching of O2(1Δg) by nitroxide radicals [1]. We have been applying this

phenomenon to O2(1Δg) lifetime measurement by EPR. In this paper, we focused on trityl radical as

another probe molecule for O2(1Δg) utilizing DEP. Trityl is one of stable radicals which have

recently been used for spin probe method. To evaluate trityl as a probe, we determined enhancement

factors of DEP generated on trityl radical by time-resolved EPR method. The mechanism of DEP in

trityl radical – O2(1Δg) system is discussed.

Figure 1 shows a time resolved (TR-) EPR spectrum

observed by the laser irradiation of 5,10,15,20-

tetraphenyl-21,23-porphyrin (TPP) – trityl mixture in

1,4-dioxane solution, together with a continuous wave

(CW-) EPR spectrum of trityl radical. The peak in the

TR-EPR spectrum appeared at the same magnetic field

position in the CW-EPR spectrum. Because O2(1Δg) is

produced by the energy transfer from excited triplet TPP

to oxygen in the air-saturated solution, the signals in the

spectrum are assigned to the spin-polarized trityl radical

by the quenching of O2(1Δg).

Figure 2 shows a time profile of EPR signal

intensity after laser irradiation for TPP – trityl system.

Enhancement of EPR signal intensity due to the DEP

was seen from 0 to 20 μs. The time profile was well

reproduced by Bloch and kinetic equations of O2(1Δg)-

trityl quenching system with DEP enhancement factor as

a fitting parameter.

We will discuss the mechanism of DEP in trityl

radical – O2(1Δg) system on the basis of DEP theory for

radical-triplet pair system [1,2].

References

1. A. Kawai, K. Shibuya, J. Photochem. Photobiol. C, 2006, 7, 89-103. 2. A. I. Shushin, J. Phys. Chem. A, 2014, 118, 11355−11363.

Figure 1. TR- and CW-EPR spectra of

trityl radical

Figure 2. Time profile of EPR signal of

trityl radical with O2(1Δg).

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EPR Study of the Mobility of Spin Labels attached to a dsDNA

Ivan Timofeev,1,3

Andrei Kuzhelev,2,3


Matvey Fedin,1,3


1International Tomography Center SB RAS. Institutskaya ЗА, Novosibirsk, 630090, Russia 2N.N. Voroztsov Novosibirsk Institute of Organic Chemistry SB RAS, Pr. Lavrentjeva 9,

Novosibirsk, 630090, Russia 3Novosibirsk State University, Pirogova 2, Novosibirsk, 630090, Russia


Pulsed dipolar EPR spectroscopy is widely used in structural studies of biological systems. In

most cases biopolymers are diamagnetic, therefore site-directed introduction of spin labels is

required. Stable nitroxides with various linkers have been widely employed as spin labels in

proteins and nucleic acids. Even more recently, triarylmethyl (trityl, TAM) radicals began to be used

as spin labels for distance measurements in model systems and biomolecules. In this work we

studied and compared the mobility of nitroxide and TAM based spin labels attached to model

double-stranded (ds) DNA.

To perform precise distance measurements in nucleic acids (NA) using pulsed dipolar EPR

spectroscopy it is essential to ensure covalent attachment of spin label and estimate the amount of

free (non-bound) radicals. We used CW EPR spectroscopy to determine these two criteria.

Simulations of room-temperature CW EPR spectra of dsDNA in liquids allowed us to obtain

rotational correlation times of radicals and correlate them with flexibility and dimensions of labels.

It was shown that the concentration of impurities (in the form of free spin labels or spin-labeled

oligonucleotides (single strands)) is low enough to influence distances obtained by pulse dipolar

EPR experiments.

Comparison of the obtained distance distribution revealed that the accuracy (width) of distance

distributions obtained by double electron−electron resonance (DEER/PELDOR) strongly depends

on the type of the spin label (radical). Replacement of both nitroxides by TAMs in the same spin-

labeled duplex allows narrowing of the distance distributions by a factor of 3. Replacement of one

nitroxide by TAM (orthogonal labeling) leads to a less pronounced narrowing, but at the same time

gains sensitivity in DEER experiment due to efficient pumping on the narrow EPR line of TAM [1].

References

1. G. Yu. Shevelev, O. A. Krumkacheva, A. A. Lomzov, A. A. Kuzhelev, D. V. Trukhin, O. Yu. Rogozhnikova, V. M. Tormyshev, D. V. Pyshnyi, M.V. Fedin, E. G. Bagryanskaya, J Phys Chem B, 2015, 119, 13641−13648.

Acknowledgements


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EPR study of intra- and intermolecular exchange

interactions in [Cu(hfac)2LEt

]2 compound

Sergey Tumanov,1,2

Irina Obsharova,1 Svyatoslav Tolstikov,

1 Victor Ovcharenko,

1

Matvey Fedin,1,2

Sergey Veber1,2

1International Tomography Center, SB RAS, 630090 Novosibirsk, Russia

2Novosibirsk State University, Pirogova str.2, 630090, Novosibirsk, Russia


Copper-nitroxide-based molecular magnets are interesting and perspective systems as some of

them exhibit magnetic anomalies similar to ones in spin-crossover compounds. Dimer complex of

copper(II) hexafluoroacetylacetonate with imidazolyl-substituted nitronyl nitroxide

([Cu(hfac)2LEt

]2) has magnetic anomaly within the temperature range of 30-100 K where its value

of the effective magnetic moment decreases from 3.2 to 2.6 μB. Such behavior can be caused by

magneto-structural rearrangements or by strong (J ~ 30-50 cm-1

) intermolecular exchange

interactions. As was shown earlier, EPR is a choice technique to study intra- and intermolecular

interactions in Cu(hfac)2LR compounds[1]

[Cu(hfac)2LEt

]2 compound has been studied using Q-band continuous wave electron

paramagnetic resonance (CW EPR) spectroscopy. The EPR spectra observed were found

temperature-dependent (fig. 1). At room temperature EPR spectrum contains single unresolved line

while at 10 K it is similar to a spectrum of copper(II) ion in octahedral coordination environment.

On the basis of the XRD data analysis we proposed that there is the main intermolecular exchange

interaction channel involving NO groups of the

neighboring molecules. Other feasible exchange

pathways are expected to be much weaker. The

intramolecular exchange interaction between

copper(II) ion and NO group of the coordinated

nitroxide radical was also considered in the

simulation model proposed. Temperature

dependence of EPR spectra of NO-Cu-Cu-NO

clusters was simulated using modified Bloch

equations. It was shown that unpaired electrons of

the NO groups of neighboring molecules pair at

low temperature thus resulting in decreasing of

the effective magnetic moment. At high

temperature the EPR spectrum contains

unresolved single line due to the intramolecular exchange interaction between copper(II) ion and

the nitroxide radical. Magnetoresonance parameters obtained from simulation of EPR spectra of

[Cu(hfac)2LEt

]2 compound qualitatively describe the temperature dependence of its effective

magnetic moment.

References

1. M. V. Fedin, S. L. Veber, E. G. Bagryanskaya, V. I. Ovcharenko. Coord. Chem. Rev. 2015, 289, 341–356

Acknowledgements

This work was supported by FASO Russia (project 0333-2014-0001) and RFBR (No.14-03-00224 and 15-03-

07640).

Figure 1.Temperature dependence of the ERP

spectra of [Cu(hfac)2LEt

]2 compound

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133

Comparative study of EPR, structural and optical properties of CdS, TiO2

nanoparticles and CdS@TiO2 core-shell nanocomposite

Ram Kripal, Garima Vaish

Department of Physics, University of Allahabad, Allahabad, 211012, India


Transition metal oxides are a fascinating class of inorganic materials exhibiting a wide variety

of structures, properties and phenomena. In recent times, metal oxide nanocomposites have received

enormous interest due to their applications in diverse areas such as photocatalysis, environmental

remediation and energy generation. Modification of a semiconductor metal oxide with another

semiconductor can enhance charge separation and hence promote interfacial charge transfer. CdS

and TiO2 nanoparticles are synthesized via co-precipitation method and sol-gel method,

respectively, further, CdS-TiO2 nanocomposite is prepared by a simple thermal decomposition

approach. The prepared materials were characterized by X-ray Diffraction (XRD) analysis, Fourier

transform infra-red spectroscopy(FT_IR), Electron Paramagnetic Resonance Spectroscopy(EPR)

and UV visible analysis. These materials are best suited for their applications as photo catalysts,

solar cells, water purifiers and electro chromic devices.

Keywords : Nanoparticles, XRD, FTIR, UV/Visible, EPR.

References : 1. S.S. Srinivasan, J. Wade, E.K. Stefanakos Visible light photocatalysis via CdS/TiO2 nanocomposite materials J.

Nanomater., 2006 (2006), pp. 1–7 2. S.Vidya, Amitava Patra, Ashok CdS @TiO2 and ZnS@TiO2 core–shell nanocomposites: Synthesis and optical

properties 3. A.K. Ganguli, T. Ahmad, S. Vaidya, J. Ahmed Microemulsion route to the synthesis of nanoparticles. Pure Appl.

Chem., 80 (2008), pp. 2451–24

Acknowledgement : The authors are thankful to the Head of Department of Physics, University of Allahabad for

providing departmental facilities.

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134

Magnetic Properties of CoII

with Large ZFS:

Experimental and Computational Study

J. Nehrkorn,1,2

Sergey L. Veber,3,4

E.A. Suturina,4 L.A. Zhukas,

3,4 I. Fomina,

5 A. Belov,

6 E. Colacio,

7

E.V. Fursova,3 P. Cucos,

8 M. Andruh,

8 J. Krzystek,

9 S. Stoll

†, K. Holldack

10 and A. Schnegg

2

1Department of Chemistry, University of Washington, Box 351700, Seattle, United States

2Berlin Joint EPR Lab, Institute for Nanospectroscopy, Helmholtz-Zentrum Berlin für Materialien und

Energie, Kekuléstraße 5,12489 Berlin, Germany 3International Tomography Center SB RAS, Institutskaya ЗА, 630090, Novosibirsk, Russia

4Novosibirsk State University, Pirogova str.2, 630090, Novosibirsk, Russia

5N.S. Kurnakov Institute of General and Inorganic Chemistry, RAS, Leninsky Prosp. 31, 119991 Moscow,

GSP-1, Russia 6A.N. Nesmeyanov Institute of Organoelement Compounds, RAS, Vavilova str. 28, 119991 Moscow, Russia 7Departamento de Quımica Inorganica, Facultad de Ciencias, Universidad de Granada, 18071 Granada,

Spain 8Inorganic Chemistry Laboratory, Faculty of Chemistry, University of Bucharest, Str. Dumbrava Rosie no.

23, 020464 Bucharest, Romania 9National High Magnetic Field Laboratory (NHMFL), Florida State University, Tallahassee, Florida 32310,

United States 10

Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin

für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany


Transition metal ions (TMIs) are very important not only in chemistry and biology, where they

play a crucial role in many processes, but also in physics where they are considered as key units for

perspective data storage devices based on single-molecule magnets (SMMs). The ability of SMM to

store the magnetization caused by spin-reversal barrier which originates from the zero field splitting

(ZFS) of the system. Small and moderate values of ZFS (up to 20 cm-1

) can be measured

experimentally with required accuracy, while for the very large ZFS (up to 200 cm-1

) such

techniques are quite complicated or give only estimation of ZFS. In turn, Frequency-Domain

Fourier-Transformed THz-EPR spectroscopy covers the required frequency range and thus is a

choice technique for investigation of ZFS in TMIs.

In this work we present a thorough study of six high-spin CoII complexes with the ZFS ranging

from ~ 50 cm-1

to 175 cm-1

[1]. FD-FT THz-EPR data were complemented with X-band spectra and

magnetic susceptibility measurements. This broad experimental ground was used to test the validity

of the different magnetic models (effective spin 1/2, spin 3/2, Lines model, total angular momentum

J) and to determine the magnetic resonance parameters within these models. The performed

quantum chemical calculations were benchmarked by comparison to the experimental results and

that allowed further insight on the examined magnetic models. The spin 3/2 model was confirmed

as most relevant to the majority of studied CoII complexes.

References

1. J. Nehrkorn, S.L. Veber, et.al. “Probing effective models for the magnetic properties of CoII with large ZFS:

experimental and computational study”. in preparation

Acknowledgements

S.L.V. and L.A.Z. acknowledge the support by the RFBR (grants No. 14-03-00224 and 15-03-07640) and the RSF

(grant No 14-13-00826). L.A.Z. also acknowledges the HZB international summer student program.

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135

EPR and optical absorption study of Fe3+

doped mono hydrated

Dipotassium Stannic chloride

Ram Kripal and Awadhesh Kumar Yadav

EPR Laboratory, Department of Physics, University of Allahabad, Allahabad-211002, India

Tel: 91-532-2470532; Fax: 91-532-2460993

E-mail: [email protected]; [email protected]

Electron paramagnetic resonance (EPR) study of Fe3+

ion doped dipotassium stannic chloride

(K2SnCl4.H2O, DPSC) single crystal is performed at X band frequency and liquid nitrogen

temperature. The Zeeman g factor, axial zero field splitting parameters and rhombic zero field

splitting parameters of Fe3+

ion in DPSC are determined with the help angular dependence of EPR

spectra. Fe3+

ion enters the crystal lattice substitutionally replacing the K+ ion. The optical

absorption spectra are recorded at room temperature in the wavelength range 195-1100 nm. The

transitions are assigned from the ground state 6A

1 g (S) to different exited states of Fe3+

ion. The

observed band positions fitted by four parameters, Racah inter-electronic repulsion parameters (B

and C), cubic splitting parameters (Dq) and Trees correction (α) yield: B = 831cm-1

, C =2198cm-1

,

Dq =820 cm-1

, and α = 90 cm-1

.

Keywords: A. Inorganic compounds; B. Crystal growth; D. Crystal fields; D. Electron

paramagnetic resonance; D. Optical properties.

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136

Zero-Field Splitting and Its Temperature Dependence in a High-Spin Co(I)

Clathrochelate Studied by FD-FT THz-EPR Spectroscopy

Joscha Nehrkorn,1,2

Sergey L. Veber,3,4

Liudmila A. Zhukas,3,4

Valentin V. Novikov,5

Yulia V. Nelyubina,5 Yan Z. Voloshin,

5 Karsten Holldack,

6 Stefan Stoll

1 and Alexander Schnegg

2

1Department of Chemistry, University of Washington, Box 351700, Seattle, USA

2Berlin Joint EPR Laboratory, Institut für Nanospektroskopie, Helmholtz-Zentrum Berlin für Materialien

und Energie, Kekuléstr. 5, D-12489 Berlin, Germany 3International Tomography Center, Siberian Branch of the Russian Academy of Sciences, Institutskaya str.

3a, 630090,Novosibirsk, Russia 4Novosibirsk State University, Pirogova str. 2, 630090, Novosibirsk, Russia

5Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova str. 28,

119991, Moscow, Russia 6Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum

Berlin für Materialien und Energie, Albert-Einstein-Str. 15, D-12489 Berlin, Germany


Zero-field splitting (ZFS) is a key feature of molecular nanomagnets (MNMs), which owe their

magnetic properties to those of a single molecule rather than to collective effects. It results from

spin-spin and spin-orbit interaction and is known as a sensitive probe of subtle effects on the

electronic structure. Hereby we demonstrate at the first time that ZFS is also sensitive to the

intermolecular interactions (IMIs) which are of high importance for slow relaxation of the

magnetization in single-molecule magnets and IMI-coupled networks of MNMs for quantum

computing [1]. For this sake the high-spin cobalt(I) clathrochelate was studied by high-end

frequency-domain Fourier-Transform THz-EPR spectroscopy. The obtained high quality spectra

allowed us to observe ZFS (D = 16.43(1) cm-1

and E = 0.0(1) cm-1

at 5K) and trace its unusual

temperature dependence: it decreases by 1% when the temperature is increased from 2.7 to 38 K.

The discovered temperature dependence of the ZFS is rationalized by weak chain-like

antiferromagnetic IMIs with J of only a few per mille of D. This small effect occurs in a compound

where the metal ions are well-isolated from the environment so that the IMIs are really weak.

The observation of such subtle effects is currently exceptional, as it requires high-purity

samples with narrow line widths and high-end spectroscopy, further progress in high-frequency

EPR instrumentation may soon make them more widely accessible. Although further evidence is

desirable to assign the observed effect unequivocally to IMIs, the proposed model might already be

useful for identifying the type of IMI and estimating their strength in MNMs especially for the

targeted design of IMI-coupled networks of MNMs for quantum computation.

References:

1. J. Nehrkorn, S.L. Veber, L.A. Zhukas, et.al. “Revealing Intermolecular Interactions by Temperature Dependence of Zero-Field Splitting in a High-Spin Co(I) Complex”. in preparation

Acknowledgements:

S.L.V. and L.A.Z. acknowledge the support by the Russian Science Support Foundation (grants no. 14-03-00224

and 15-03-07640). L.A.Z. also acknowledges the HZB international summer student program.

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137

AUTHOR INDEX

Açıkgöz M.................................................... 47

Ackermann K. .............................................. 55

Adonin N. ..................................................... 88

Afanasyeva E. .............................................. 95

Affronte M. .................................................. 34

Aleksandrova G...................................... 70, 71

Ambe C. ....................................................... 49

Andreev N. ................................................... 72

Andruh M. .................................................. 134

Anuradha K. ............................................... 105

Arakawa K. .................................................. 96

Artyomov M. ........................................ 97, 103

Asada M. .......................................... 58, 80, 84

Asami T. ....................................................... 61

Asano M. ...................................................... 61

Asatryan H. ................................................ 103

Audran G. ....................................... 64, 74, 102

Babaylova E. ................................................ 40

Bagryanskaya E.............. 40, 82, 85, 88, 89, 94

........................ 102, 108, 113, 114, 115, 131

Banerjee D.................................................... 98

Becker R. ...................................................... 77

Bedilo A. ...................................................... 75

Belov A. ..................................................... 134

Berezin A. .................................................... 99

Bezmaternykh L. ........................................ 125

Bhagyashree K.S. ................................... 33, 92

Bhat S.N. ...................................................... 98

Bhat S.V. .................................. 33, 92, 98, 105

Blank A. ....................................................... 35

Blinco J. ....................................................... 29

Bobko A. ................................................ 27, 63

Bode B.......................................................... 55

Bolton D.R . ................................................. 32

Bottle S. ........................................................ 29

Bowen A. ..................................................... 65

Bowman M. .................................................. 86

Breitgoff F. ................................................... 28

Brémond P...................................... 64, 74, 102

Brown L. ...................................................... 52

Bye M. .......................................................... 31

Castellanos S. ............................................... 77

Chen J. ........................................................ 100

Chichkov V. ................................................. 72

Colacio E. ................................................... 134

Collauto A. ................................................... 31

Coronado E. ................................................. 34

Cucos P. ..................................................... 134

Damle R. ...................................................... 92

Demakov P. ................................................ 124

Dhimitruka I. ................................................ 27

Dikov M. ...................................................... 27

Dobrynin S. .................................................. 43

Doll A. ......................................................... 28

Dolmaa G. .................................................... 70

Donohue M. ........................................... 51, 52

Driesschaert B. ....................................... 27, 63

Du J. ....................................................... 30, 79

Duan Y. ........................................................ 34

Dwivedi P. ................................................. 101

Dybtsev D. ................................................. 124

Dzuba S. ........... 26, 86, 95, 104, 109, 119, 129

Edeleva M. ................................................. 102

El Mkami H. ................................................ 32

Ema F. .......................................................... 60

Epel B. ................................................... 53, 73

Eremina R. ........................................... 72, 125

Eubank T. ..................................................... 27

Evans J. ........................................................ 27

Fedin M. ................... 40, 77, 82, 85, 88, 89, 94

...... 108, 113, 114, 115, 124, 126, 131, 132

Fokin A. ..................................................... 103

Fomina I. .................................................... 134

Formaggio F. ............................................. 129

Franconi J.-M. .............................................. 64

Fujii Y. ................................................... 56, 66

Fukuda A. .................................................... 66

Fursova E. .................................................. 134

Gaita-Ariño A. ............................................. 34

Garbuio L. .................................................... 59

Gascon J. ...................................................... 77

Gavrilova T. ................................................. 72

Geng J. ......................................................... 79

Ghirri A. ....................................................... 34

Giannoulis A. ............................................... 55

Gilmutdinov I............................................... 72

Gnutek P. ..................................................... 47

Golbeck J. .................................................... 41

Goldfarb D. .................................................. 31

Golysheva E. .............................................. 104

Gorbunov D. ................................................ 87

Gorka M. ...................................................... 41

Gostev F. ...................................................... 41

Goveas L. ................................................... 105

Grassi G. ...................................................... 59

Gritsan N. ..................................................... 87

Gromov I. ..................................................... 57

Hagiwara M. .............................................. 123

Halpern H..................................................... 53

Hara H. ............................................... 106, 120

Hara S. ....................................................... 123

Häussinger D. ........................................ 59, 69


138

Hegde B........................................................ 68

Hetzke T. ...................................................... 65

Hiiragi K. ..................................................... 56

Hill S. ........................................................... 34

Hirata H. ....................................................... 39

Hiroi Z. ....................................................... 123

Höfer P. ........................................................ 57

Holldack K. ........................................ 134, 136

Hosoda H.................................................... 106

Hunter R.I..................................................... 32

Ifuku K. ........................................................ 58

Ikoma T. ........................................... 42, 49, 50

Inanami O. .................................................... 39

Irtegova I. ........................................... 107, 127

Isaev N. ........................................................ 95

Ishikawa Y. .................................................. 66

Ivanov K. .............................................. 81, 121

Ivanov M. ....................................... 88, 89, 108

Jeschke G. ........................................ 28, 59, 69

Jiang M. .................................................. 44, 76

Kandrashkin Y. ............................................ 62

Kapteijn F. .................................................... 77

Kardash M. ................................................. 109

Karpova G. ................................................... 40

Kato M. ...................................................... 130

Kawai A. .................................................... 130

Khramtsov V. ........................... 27, 39, 63, 130

Khutsishvili S. .............................................. 70

Kikuchi H. .................................................... 66

Kim M. ....................................................... 116

Kimura F. ................................................... 123

Kimura T. ................................................... 123

Kirilyuk I. ................................. 39, 40, 43, 114

Kiryutin A. ................................................. 121

Kitahara Y. ................................................. 123

Kobori Y. ..................................................... 60

Kolokolov D. ................................................ 82

Komarovskikh A. ................................. 45, 110

Komijani D. .................................................. 34

Koonjoo N. ................................................... 64

Kothe G. ....................................................... 81

Kozanecki M. ............................................. 111

Kripal R. ............... 91, 101, 112, 128, 133, 135

Krisyuk V. .................................................... 99

Krumkacheva O. .... 40, 85, 113, 114, 115, 131

Krzystek J. .................................................. 134

Kubota H. ..................................................... 39

Kubota S. .................................................... 123

Kulik l. ......................................................... 90

Kuprikova N. ................................................ 43

Kupriyanov I. ............................................. 110

Kurashov V. ................................................. 41

Kuzhelev A. ........... 40, 85, 113, 114, 115, 131

Kuznetsov G. ............................................. 108

Ladizhansky V. ............................................ 52

Langen R. ..................................................... 68

Lee H. ........................................................ 116

Lee S. ........................................................... 66

Leporini D. ................................................... 98

Lesnichaya M............................................... 70

Li Y. ....................................................... 44, 76

Lin T.-S. ....................................................... 81

Link G. ......................................................... 81

Liodl A. ...................................................... 125

Liu H.-G. .................................................... 117

Liu W. ........................................................ 100

Loskutov V. ............................................... 127

Lukaschek M. .............................................. 81

Lukina E....................................................... 90

Maeda K........................................... 38, 42, 96

Mamedov M................................................. 41

Marque S. ....................................... 64, 74, 102

Maryasov A. ................................................ 86

Massot P. ..................................................... 64

Matsubara A................................................. 66

Matsumoto S. ............................................... 39

Matsuoka Y. ............................................... 118

Matveeva A. ............................................... 119

Mchaourab H. S. .......................................... 31

McKay J. ...................................................... 32

Mellet P. ....................................................... 64

Milikisiyants S. ............................................ 52

Minakawa S. .............................................. 120

Mino H. ............................................ 58, 83, 84

Mishra S. ...................................................... 31

Mitsudo S. .............................................. 56, 66

Miura S. ....................................................... 66

Miura T. ....................................................... 42

Mizusaki T. .................................................. 66

Möbius K. .................................................... 41

Morozov D. .......................................... 43, 114

Moshkina E. ............................................... 125

Motion C. ..................................................... 32

Munro R. ...................................................... 52

Müntener T. ................................................. 69

Murai H. ....................................................... 42

Nadolinny V........................... 45, 99, 108, 110

Nadtochenko V. ........................................... 41

Nagashima H. .............................................. 83

Nakagawa K......................................... 73, 120

Nakamura T. ................................................ 80

Narioka M. ................................................... 56

Nasalevich M. .............................................. 77

Nasibulov E. .............................................. 121


139

Nawa K. ..................................................... 123

Nehrkorn J. ......................................... 134, 136

Nelyubina Y. .............................................. 136

Nishimura T. ................................................ 58

Nogueira E. .................................................. 59

Novikov V. ................................................. 136

Obsharova I. ............................................... 132

Ohmichi E. ..................................... 25, 54, 122

Ohta H. ................................... 25, 54, 122, 123

Ohya K. ........................................................ 66

Okamoto T. .......................................... 54, 122

Okamoto Y. ................................................ 123

Okubo S................................................ 25, 123

Osadchii D.................................................... 77

Osuka A........................................................ 60

Ovanesyan K. ............................................. 103

Ovcharenko V. ............................. 94, 107, 132

Palyanov Yu. ........................................ 45, 110

Parkhomenko D.......................................... 102

Parzy E. ........................................................ 64

Petrosyan A. ............................................... 103

Poddutoori P. ................................................ 62

Polienko Y............................................ 43, 114

Polyhach Y. .................................................. 28

Popov A........................................................ 90

Poryvaev A. .................................. 82, 124, 126

Potapov A. .................................................. 103

Pribitzer S. .................................................... 28

Prikhod’ko S. ............................................... 88

Prisner T. ...................................................... 65

Pyshny D. ..................................................... 40

Pyshnyi D. ............................................ 85, 114

Rakhmanova M. ......................................... 110

Ramos-Fernandez E. .................................... 77

Rautskii M. ................................................. 125

Reek N.......................................................... 77

Rogozhnikova O. ....................... 102, 113, 115

Rokeakh A.................................................... 97

Rong X. ........................................................ 79

Rudowicz C. ......................................... 47, 111

Saito S. ......................................................... 60

Sakurai T. ............................................. 25, 123

Samoilova R. .............................................. 129

Sato F. .......................................................... 58

Sato K. .......................................................... 60

Savitsky A. ............................................. 36, 41

Sawamura D. .............................................. 120

Schnegg A. ......................................... 134, 136

Segawa T. ..................................................... 28

Selenko P...................................................... 69

Semenov A. .................................................. 41

Shelaev I. ...................................................... 41

Shelkovnikov V. .......................................... 89

Shevelev G. .................................... 40, 85, 114

Sheveleva A. .......................... 82, 89, 124, 126

Shi F. ...................................................... 78, 79

Shiddiq M. ................................................... 34

Shundrin L. ........................................ 107, 127

Shundrina I................................................... 89

Shuvarakova E. ............................................ 75

Singh V. ..................................................... 128

Smirnov A. ............................................. 51, 52

Smirnova T. ........................................... 51, 52

Smith G.M. .................................................. 32

Stepanov A................................................... 82

Stoll S. ............................................... 134, 136

Strizhakov R. ............................. 113, 114, 115

Su J. ........................................................... 100

Suess B. ....................................................... 65

Sugisaki K. ................................................... 60

Sukhanov A. ................................................ 93

Sukhov B. .............................................. 70, 71

Sundramoorthy S. ........................................ 53

Suturina E. ................................................. 134

Syryamina V. ................................. 86, 95, 129

Tachikawa T. ............................................... 60

Takahashi Hideyuki ....................... 25, 54, 122

Takahashi Hirona ....................................... 130

Takahashi Susumu ....................................... 46

Takui T......................................................... 60

Tamura T. .................................................. 130

Tanabe M. .................................................... 60

Theillet F.-X. ............................................... 69

Thiaudière E................................................. 64

Tian C. ......................................................... 67

Tikhonov N. ................................................. 70

Timofeev I. ................................................ 131

Tipikin D. ..................................................... 53

Tolstikov S. ................................................ 132

Tormyshev V. ................ 40, 85, 102, 113, 115

Tretyakov E. ................................ 87, 102, 107

Tripathi U..................................................... 91

Troitskaya T. ...................................... 113, 115

Trukhin D................................... 102, 113, 115

Tseytlin M. ................................................... 53

Tsvetkov Y................................................. 129

Tumanov A. ............................................... 132

Tyurin V....................................................... 93

Umegaki C. .................................................. 56

Vaish G. ..................................................... 133

Vakul’skaya T. ............................................. 70

van der Est A. ........................................ 61, 62

van der Vlugt J. ............................................ 77

Vanin A. ....................................................... 37


140

Vasiliev S. .................................................... 66

Vasilieva N. ........................................ 107, 127

Vazhenin V. ............................................... 103

Veber S. ...... 77, 88, 89, 94, 108, 132, 134, 136

Vieth H.-M. ................................................ 121

Vogel M. ...................................................... 65

Volodin A. .................................................... 75

Voloshin Y. ................................................ 136

von Nidda H.-A. ......................................... 125

Voronkova V. ............................................... 93

Voynov M. ............................................. 51, 52

Wakikawa Y. ................................................ 49

Walsh L. ....................................................... 29

Wang S. ........................................................ 52

Ward T. ........................................................ 59

Woodward J. ................................................ 96

Xiong Y. ....................................................... 67

Yadav A. ............................................ 101, 135

Yagai S. ........................................................ 49

Yago T. ........................................................ 81

Yamamori H. ............................................... 66

Yamauchi S. ................................................. 60

Yang H. .................................................. 44, 76

Yasuda Y. .................................................... 61

Yasui H. ....................................................... 39

Yatsyk I. ............................................... 72, 125

Yoshizawa D. ............................................. 123

Yu L. ............................................................ 67

Yulikov M. ............................................. 59, 69

Yurkovskaya A. ......................................... 121

Yuryeva O. ................................................. 110

Zheng W.-C. .............................................. 117

Zhivetyeva S. ............................................. 102

Zhou L. ........................................................ 67

Zhukas L. ........................................... 134, 136

Zhurko I. ...................................................... 43

Zimmermann K. ........................................... 59

Zueva E. ..................................................... 107


141

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Documents

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