石田 俊正(いしだ としまさ)

Toshimasa ISHIDA

 

l  CV etc.(English)   略歴他(日本語)

 

l  Research

 

l  Publication list

 

l  講義資料

 


 

l  CV etc.

 

Office

Room 205, Fukui Institute for Fundamental Chemistry, Kyoto University

 

Phone/Fax

+81-75-711-7838

 

Email

ishida@fukui.kyoto-u.ac.jp  (Replace @ with the normal at-mark.)

 

Research Area

Computational Chemistry/Theoretical Chemistry

 

Research Interest

Molecular Photochemistry, Reactions of biomolecules, Generation of potential energy surfaces

 

Keywords

Molecular Photochemistry, Reactions of biomolecules, PES, Non-adiabatic transition

 

Education

Graduated from Graduate School of Science, The University of Tokyo

 

Degree

Doctor of Science, The University of Tokyo

 

Work Experience

Apr. 1989   Research Associate, Faculty of Arts and Sciences, Shizuoka University

Apr. 1995   Associate Professor, Faculty of Arts and Sciences, Shizuoka University

Oct. 1995   Associate Professor, Faculty of Engineering, Shizuoka University

Apr. 2002   Associate Professor, Institute for Molecular Science

Apr. 2004   Associate Professor, Faculty of Engineering, Shizuoka University

Oct. 2004   Associate Professor, General Division, Fukui Institute for Fundamental Chemsitry, Kyoto University

 

 

Apr. 1996 to Mar. 1997 Long-term Researcher Abroad (Ministry of Education Culture, Sports, Science and Technology Japan) at Department of Chemistry, Northwestern University with Prof. George C. Schatz

 

Membership

The Chemical Society of Japan

Japan Society of Molecular Science

Society of Computer Chemistry, Japan

American Physical Society

 

 

l  略歴他

 

居室 

福井謙一記念研究センター205

 

電話・FAX 

075-711-7838

 

電子メールアドレス

ishida@fukui.kyoto-u.ac.jp  (@を半角に変更して下さい)

 

【研究分野】

計算化学・理論化学

 

【現在の研究課題】

光機能分子・生体分子の反応・ポテンシャル面生成法

 

【研究内容キーワード】

光機能分子・生体分子・ポテンシャル面・非断熱遷移

 

【学歴】

19893月東京大学理学系大学院相関理化学専攻博士課程修了

 

【学位】

19893月理学博士(東京大学)

 

【略歴】

19894月 静岡大学教養部助手

19954月静岡大学教養部助教授

199510月静岡大学工学部助教授

20024月岡崎国立共同研究機構分子科学研究所助教授(流動部門)

20044月静岡大学工学部助教授

200410月京都大学福井謙一記念研究センター助教授

20074月同准教授

 

 

19964-19973月 米国Northwestern大学化学(George C. Schatz教授)(文部省在外研究員(若手)

 

【所属学会】

日本化学会

日本分子科学会

日本コンピュータ化学会

米国物理学会

 

l  Research

 

 We are interested in reactions in the excited state induced by photons. One example is retinal.

Retinal is embedded in Rhodopsin protein, which is responsible for vision of vertebrate animals including human. When the retinal is exposed to light, the 11-cis form is excited and isomerized to the all-trans one. This process has been investigated experimentally as well as theoretically.

 We carried out on-the fly classical dynamics calculations combined with ab initio quantum chemical computations. The 9-cis form product in addition to the all-trans one is generated in the present gas-phase calculation for the 12p model, despite that the 9-cis generation is suppressed in protein. We have found that energy relaxation on the ground state occurs in two steps in the 12p model. In the first step a metastable intermediate state is formed at ~100fs after photoexcitation at the energy around 20~40kcal/mol down from the excited potential energy surface, then it further relaxes to the energy around 60~80kcal/mol from the excited surface, leading to the final state (second step). This relaxation pattern can be seen in all the three pathways to the all-trans, 9-cis and (reverted) 11-cis form. Fourier transformation analysis reveals that the effective vibrational frequencies of the intermediate state are 1,600-2000 cm-1, which can be attributed to the conjugate CC bond frequencies in the electronically ground state. The two step relaxation may be due to dynamical barriers. The two step relaxation is not revealed in the smaller 6p model. The branching ratio is about 1:1:2 for the all-trans, 9-cis, and 11-cis form generation.

 We also performed reaction simulation for 9-cis retinal. We have found that  the reaction time for 9-cis retinal is slower than 11-cis analogue and that the quantum yield is smaller, which is in agreement with experiments. This is due to the trajectory trapping in an energy barrier in the excited state.

    We plan to carry out simulations of retina molecules with protein environment, that is, Rhodopsin and Isorhodopsin.