Generation of Broader Impact of Research Activities

through International Partnering and Collaborations

NSF’s Broader Impact review criteria encourage its research force to engage in activities that partner with researchers from international institutions.

The PI at Columbia University has established a user friendly Colaboratory for a range of topics of fundamental and technological interests in areas such as molecular and supramolecular photochemical and photophysical investigations. The senior international collaborators participating in these collaborations are shown in this slide.

International partnering and exchanges produce enhancement of the training of faculty, students and postdoctoral associates, exposing researchers to a powerful diversity of ideas, methods and mentoring.

KomatsuJapan

InoueJapan

AdamGermany

BraunGermany

FeringaHolland

Da SilvaPortugal

KraeutlerAustria

BuchachenkoRussia

The success of the project can be evaluated by the fact that in the last three years coauthored publications have resulted or are in press with each of the senior collaborators indicated. The support of the National Science Foundation through the following grants is gratefully acknowledged: Understanding Chemical Complexity & Diversity Through Collaboration and Integration (CHE 07-17518).

WhittakerAustralia

ArsuTurkey

YagciTurkey

JinChina

RoomEstonia

ZeccaItaly

OttavianiItaly

ZapataMexico

ScaianoCanada

FlohrGermany

MurataJapan

LevittEngland

HoreswillEngland

Nicholas J. TurroColumbia University

Locations of International Collaborators

Japan: Prof. Koichi Komatsu and Prof. Yosujiro Murata, Kyoto U.The simplest molecule, H2 exists as two completely distinct species with its nuclear spins are parallel ( ) or antiparallel (). The interconversion of two spin isomers of H2 inside a buckyball was achieved (Figure left) with oxygen as a spin catalyst, showing that the H2 inside C60 can communicate with the outside world.Reference: J. Am. Chem. Soc., 130, 10506 (2008).

Can a H2 molecule, incarcerated in a buckyball, communicate with the outside world?Imagine the simplest molecule, H2, permanently incarcerated inside

one of the loveliest molecule, buckyball, C60. Can the incarcerated H2 communicate with molecules in the outside world? The question (see below) was probed by a combination of nuclear magnetic resonance (NMR) spectroscopy and spin chemistry in collaborations with scientists in Russia and in Japan. The Russia collaborator assisted in the theoretical interpretation of the NMR relaxation of H2 and of H2@C60. The Japanese collaborators developed the synthesis ofH2@C60 .Russia: Prof. Anatoly Buchachenko, Moscow

State U.The NMR relaxation of H2@C60, the simplest molecule incarcerated in a buckyball, in the presence of relaxants was measured for the first time. The experiments (Figure right) demonstrate that the H2 inside C60 can “communicate” with paramagnetic molecules in the “outside world”.Reference: J. Am. Chem. Soc., 130, 2221 (2008).

International Symposium on H2@C60 held at Columbia on August 15, 2008. N. J. Turro, Columbia U., Organizer. International participants (Figure right): Malcolm Levitt (U. Southampton, UK), Toomas Room (Ins. Chem. Phys., Tallinn, Estonia). Anthony Horsewill (U. Nottingham, UK), Yasujiro Murata (U. Kyoto, Japan), Martin Saunders (Yale U., USA), Zlatko Bacic (NYU, USA), Stephen Fitzgerald (Oberlin U.). Ron Lawler (Brown U., USA).

Italy. Collaborator: Prof. M. F. Ottaviani, U. Urbino.An understanding of the supramolecular structure and dynamics of absorption of molecules on the external and internal surface of porous solids is of critical importance in a range of solid state catalysis. Electron spin resonance (Figure left) has been employed to quantitatively determine the surface structure and dynamics of organic molecules adsorbed on the external surface of the important MFI family of catalysts.Reference: J. Am. Chem. Soc., 130, 11344-11354 (2008).

white light (400-800nm) UV light (366nm)

Austria. Collaborator; Prof. Bernhard Kraeutler, U. Innsbruck. The decomposition of chlorophyll in banana was found to produce a blue fluorescent species (Figure right) whose concentration tracks the ripening of the bananas. Such species are also found as those in degreened leaves, suggest that chlorophyll degrades through a related pathway in leaf senescence and fruit ripening.Reference: Angew. Chem., 47, 8954 (2008).

Germany. Collaborator: Andreas Flohr, Proctor & Gamble, Schwalbach.A novel method for the surface cross-linking (Figure left) of superabsorbent polymer particles used for manufacturing diapers has been developed. Polymer materials produced have superior properties such as liquid flow thought the fluid particle bed and capacity. In addition, the process is projected to be more energy efficient (through green chemistry) than the current thermal method for cross-linking.Reference: J. Appl. Polymer Sci., 111, 2163-2170 (2009).

Green diaper production, fluorescent bananas and tracking molecules adsorbed on porous catalytic solids

C P

O O

Ph

Ph

S

OSH

h

P

O

Ph

PhC

O (O2)

polymerO

O

Turkey. Collaborator, Prof. N. Arsu, Yildiz U., Istanbul Acylphosphines are widely used as photoinitiators for the incustrial important process of radical polymerization. Mercaptothioxanthone was shown to act as sensitizer and coinitiator for acylphosphine photoinitiators in free radical polymerization (Figure right). Reference: Macromolecules, 41, 4631 (2008).

Germany. Collaborator: Dr. Andre Braun, U. KarlsruheThe photolithographic industry has considered the use of 157 nm lasers as a means of making smaller features in the manufacture of computer chips. Perfluorpolymers are critical materials to protect computer chips from contaminants. The photochemistry of these materials at very short wavelengths was investigated and elucidated for the first time (Figure left).Reference: J. Am. Chem. Soc., 127, 8320-8327 (2005).

Turkey. Collaborator, Prof. N. Yusuf Yagci, Istanbul Tech. University. Organic thin films of conjugated polymers such as polythiophene (Figure left) are of current interest because of their potential use in electronics and electro-optical devices. The mechanism of the photoinduced polymerization of thiophene using onium ions as photoinitiators was elucidated employing laser flash photolysis methods.Reference: Macromolecules, 40, 4481 (2007).

Photochemistry at a tool for the synthesis and study of polymers: perfluorocarbons for photolithography, the mechanism of polymer synthesis and synthesis of thin

conducting polymer films.

Cl

Cl

H

+ R-H- R

OO

- Cl

h

+ O2

Portugal: Jose P. Da Silva, U. AlgarveChlorinated aromatic compounds are environmental pollutants that have the potential to be mineralized to environmentally acceptable materials by photochemical reactions. Substitution, reduction and oxidation mechanisms of aryl chloride photoreactions were probed and elucidated with oxygen as a competitive quencher (Figure left). Reference: Photochem. Photobiol. Sci., 8, 210-216 (2009).

Japan: Yoshihiro Inoue, Osaka U.A novel mechanism for controlling the selectivity of reactions of singlet oxygen, an electronically excited state of normal oxygen (Figure left). The addition of singlet oxygen to certain double bonds was found to be extremely selective. The selectivity was found to be very dependent on conditions such as solvents and temperature.Reference: Tetrahedron, 62, 6707-6717 (2006).

Australia: Andrew Whittaker, U. QueenslandProducing immersion fluids that are transparent at 193 nm and that possess a high refractive index is an important goal for producing smaller features in making computer chips by photolithography. An empirical correlation (Figure right) was developed that allows an accurate prediction of the best candidates for such immersion fluids. Importantly, the correlation revealed that cyclic saturated hydrocarbons possess a significantly higher refractive index than linear hydrocarbons of comparable molecular weight.Reference: J. Photochem. Sci. Tech., 20, 643-650 (2007).

H

H

H

H

Controlling the selectivity of oxidation reactions, producing high refractive index materials for photolithography and cleaning up environmental pollutants with light

A

NO

O

A

H3C H

H

H3C

NO

O

Z isomer

E isomer

low enantioselectivty (up to 30% ee)

high enantioselectivty (up to 97% ee)

1O2

sterically controlled

stereoselectivephotooxidative

cleavageMDB

OH3C

(R/S)3O2

conformationally controlled

stereoselective quenching by C-

H vibrations

H

H

International graduate student exchange: Studentsadd undergraduates. Salvo, French, Australia,

Prof. Andre BraunU. Karlsruhe

Judy ChenColumbia Portugal + Italy + Israel + England

Prof. DaSilvaU. Algarve, Portugal

Columbia Portugal + Italy + Israel + England

Greg CarrollColumbia U. Groningen

Prof. Ben Feringa, U. Groningen

Columbia Netherlands

Jeremiah JohnsonColumbia U. Kyoto

Prof. Yasujiro Murata, U. Osaka

Columbia Japan

Hideaki SaitoU. Osaka, Japan Columbia U.

Prof. Yoshi InoueU. Osaka

Japan Columbia

M. Francesca Ottaviani

Prof. M. Francesca OttavianiU. Urbino, Italy

Melissa SojkaU. Karlsruhe, Germany Columbia U.

Germany Columbia

Sarah BosioU. Wuerzburg, Germany Columbia U.

Prof. Waldemar Adam,U. Wuerzburg,

Germany Columbia