Title Organic Structural Chemistry

Author(s)

Citation ICR annual report (2004), 10: 28-29

Issue Date 2004-03

URL http://hdl.handle.net/2433/65401

Right

Type Article

Textversion publisher

Kyoto University

ProfKOMATSU, Koichi

(DEng)

AssocProfKITAGAWA, Toshikazu

(DEng)

InstrNISHINAGA, Tohru

(D Eng)

InstrMURATA, Yasujiro

(D Eng)

PDLIN, Jing-Rong

(D Eng)

MURATA, Michihisa (D l)YAMAZAKI, Tetsuya (MI)

PDHAN,Aihong

(D Sc)

MIYATA, Yasuo (Dl)UTO, Takayuki (MI)

PDNOGITA, Rika

(D Sc)

PD (JSPS)ISHIDA, Shintaro

(D Sc)

StudentsLEE, Yangsoo (D3) OGAWA, Kohei (D2)YAMAZAKI, Daisuke (M2) MASAOKA, Naoki (M2)MAEDA, Shuhei (DG) MATSUBARA, Hiroaki (DG)

f---------------------

Fundamental studies are being conducted for creation ofnew functional materials with novel structures and properties.The major subjects are: synthetic and structural studies on novel cyclic :n;-conjugated systems, particularly the positivelycharged species stabilized by a-:n; interaction; synthesis of new redox-active and supramolecular :n;-systems; organo-chemical transformation of fullerene C60, specifically the synthesis of fullerene dimers and trimers by the use of mecha-nochemical solid-state reactions; synthesis and reactions of open-cage fullerene derivatives; generation of alkylated C60cation and its application for synthesis of functional materials.

GrantsKomatsu K, Appearance ofbiradical character in :n;-con-

jugated hydrocarbons by annelation with strained bicyclicframeworks, Grant-in-Aid for Scientific Research (B) (2),Apr. 2002 - Mar. 2004.

Kitagawa T, Grant-in-Aid for Scientific Research (C)(2), Apr. 2002 - Mar. 2004.

Nishinaga T, Grant-in-Aid for Young Scientists (B),Apr. 2002 - Mar. 2004.

Murata Y, Grant-in-Aid for Young Scientists (B), Apr.2002 - Mar. 2004.

Kitagawa T, CREST, Japan Science and TechnologyCorporation, Nov. 2002 - Oct. 2007.

Murata Y, Komatsu K, Academic-Industrial Coop-erative Research Fund, Aug. 2002 - Mar. 2004.

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PresentationsSynthesis of Open-Cage Fullerene Derivatives and

Encapsulation of Small Molecules, Komatsu K, Murata Y,Murata M, The 203rd Meeting of the Electrochemical So-ciety, 28 April, Paris, France.

Generation and Properties of Functionalized FullerenylCations, Kitagawa T, Lee Y, Murata Y, Cheng F, Komatsu K,225thACS National Meeting, 24 March, New Orleans, USA.

Radical Cations and Dications of Oligothiophene An-nelated with Rigid a-Frameworks, Nishinaga T, KomatsuK et al., Gordon Research Conferences on Physical Or-ganic Chemistry, 29 June, Laconia, USA.

Synthesis and Electrolytic Polymerization of a Fuller-ene-Terthiophene Dyad, Murata Y, Suzuki M, YamazakiT, Komatsu K, The 203rd Meeting of the ElectrochemicalSociety, 2 May, Paris, France.

28 TOPICS AND INTRODUCTORY COLUMNS OF LABORATORIES------

Stable Radical Cations and Dications of Oligo-thiophenes Surrounded by Bicyclo[2.2.2]octeneUnits

Oligothiophenes 1 annelated with bicyclo[2.2.2]octene(abbreviated as BCO) units were designed and synthe-sized in order to elucidate the uni-molecular properties ofcationic oligothiophenes.[l] The radical cation salts ofthe dimer and trimer and dication salts of the tetramer andhexamer have been isolated as air-stable single crystalsand their structures have been determined by X-ray crys-tallography. In these crystals, the effective inhibition of in-termolecular :It-:It interaction by BCO units was shown,[2]indicating that 1 is a suitable system for the investigationof the properties of longer oligomer dications, the uni-molecular magnetic properties of which (singlet, triplet, orindependent biradicals) are still controversial.

1(6T)2+

I. Wakamiya A, Yamazaki D, Nishinaga T, Kitagawa T, Komatsu K, J.Org. Chern., 2003, 68, 8305.2. Nishinaga T, Wakamiya A, Yamazaki D, Komatsu K, J. Am. Chern.Soc., 2004, 126, in press.

3. Kitagawa T, Lee Y, Komatsu K, J. Org. Chern., 2004, 69,263.

Electron-Transfer Induced Substitution of Al-kylated C60 Cblorides with Proton Sponge

A series of alkylated C60 chlorides 2 were found to un-dergo rapid substitution with proton sponge 3, affordingdonor-acceptor dyads 4 in good yields.[3] A chain mech-anism, initiated by a single-electron transfer from 3 to 2, isproposed on the basis of the results of rate measurements.This is the first example of the SRN1 reaction observed foralkylated C60 chlorides. The facility of such a reactionis reasonably anticipated from the inherent electronega-tivity of the fullerene core, which was demonstrated bythe reduction potential and low LUMO energy of 2. Thepresent result provides a novel practical method to synthe-size fullerene-donor dyads using a variety of electron-richaromatic compounds.

HOMO-1 HOMO LUMO

Molecular orbitals of 4

LUMO+1

100% Encapsulation of Molecular Hydrogenin an Open-Cage FuUerene

We succeeded in the synthesis of a fullerene derivative5 having a 13-membered ring orifice in 40% overall yieldbased on consumed C60 by three-step organic reactions,i.e., a reaction of C60 with a 1,2,4-triazine derivative, pho-tochemical oxidation, and insertion ofa sulfur atom on therim of the orifice.[4] A 100% encapsulation of molecularhydrogen in 5 was achieved for the first time by treatingsolid 5 at 200°C under 800 atmosphere of hydrogen for 8hours. Furthermore, when the hydrogen containing mol-ecule, H2@5, was subjected to MALDI-TOF MS at a highlaser power, H2@5 transformed its structure to H2@C60 byitself in the gas phase. This could be taken as the first step

H2(800 atm)

•200°C, 8 h

100%

...... ,'/,;j- Laser - gas-phase"0 \ .....

IH2@C60 "

4. Murata Y,MurataM,KomatsuK, Chern. Eur. J., 2003, 9,1600.5. Murata Y, Murata M, Komatsu K, J. Am. Chern. Soc., 2003, 125, 7152.

ICRANNUAL REPORT, 2003 29------