1999 Fiscal Year Final Research Report Summary
Time-Resolved Spectroscopy of Photoinduced Molecular Stractural Dynamics
| Project/Area Number |
09045038
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | Waseda University |
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Principal Investigator |
TAKAHASHI Hiroaki Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (40063622)
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| Co-Investigator(Kenkyū-buntansha) |
YUZAWA Tetsuro Waseda University, Advanced Research Institute for Science and Engineering, Assistant Professor, 理工学総合研究センター, 講師 (40261200)
ITOH Koichi Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (40008503)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Photoinduced Molecular Structure / Structural Dynamics / Time-Resolved Spectroscopy |
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| Research Abstract |
Photochemistry of Chlorpromazine : It was found that in the photoreaction of phenothiazine, chlorophenothiazine, promazine and chlorpromazine a transient X having an absorption peak at 560nm is generated from the cation radical, and from this transient another transient Y with an absorption peak at 380 nm is produced
Photochemistry of Salicylanilide : It was shown by using time-resolved IR spectra that a transient with the lifetime of 8 μs was involved in the photoreaction of salicylanilide. It was concluded based on the absence of an amide II band that the transient takes a quinoid structure.
Photochemistry of Luciferein : It was found that the time-dependence of picosecond time-resolved absorption/fluorescence spectra of luciferin can be interpreted in terms of a 4-terms model. This indicates the existence of two isomeric species of S_1.
Structure and Dynamics of the Photo-excited States of Dibenzazepine : Three transients were detected by picosecond time-resolved absorption spectroscopy. They were assigned to the S_2 state, S_1 state in the Franck-Condon state, and S_1 state in a relaxed state. The Franck-Condon S_1 state is considered to be in a butterfly-like bent structure similar to the ground state. It was concluded that the relaxed S_1 state is in a planar structure.
Photochemistry of Biphenil : It was shown that the structure of binhenyl in the S_1 state changes from a twisted form (around the central C-C bond) to a planar trans form, a structure similar to that of the T_1 state. This structural change in the Sl state occurs within 20 ps after excitation
Photochemistry of Carbazole : It was found that photo-excitation of carbazole gave rise to a formation of the cation radical and carbazyl radical in polar solvents, while only the carbazyl radical was generated in nonpolar solvents. The cation radical is generated biphotonically, while the carbazyl radical is produced monophotonically.
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