| Project/Area Number |
61430002
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理化学一般
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| Research Institution | Yokohama National University |
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Principal Investigator |
HIGUCHI Jiro Professor Faculty of Engineering, Yokohama National University, 工学部, 教授 (20017875)
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| Co-Investigator(Kenkyū-buntansha) |
YAGI Mikio Associate Professor Faculty of Engineering, Yokohama National University, 工学部, 助教授 (00107369)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 1987: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1986: ¥12,500,000 (Direct Cost: ¥12,500,000)
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| Keywords | Electron Spin Resonance (ESR) / Time-Resolved ESR / Laser / Lowest Excited Triplet State / Phosphorescent State / Intersystem Crossing / Zero-Field Splitting Constant / 分子軌道法 / スピン副準位 / ゼロ滋場分離定数 |
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| Research Abstract |
The effects of protonation and coordination to diamagnetic metal ions on the intersystem crossing (ISC) process of 2,2'-bipyridine (bpy) have been studied using a time-resolved ESR technique. The analysis of the time-resolved ESR spectra showed that the sublevel initially populated by ISC is mainly T_z in both bpy and bpyH^+, while it is mainly T_y in [Zn(bpy)]^<2+>(y and z are close to long and short in-plane molecular axes, respectively). The effects of protonation on the ISC processes of azanaphthalenes have also been studied. Following the protonation of quinoline, the sublevel initially populated changes from T_y to T_z.
Time-resolved ESR technique is very useful for the study of nonphoshhorescent and sport-lived T_1 molecules, such as trans-4,4'-diazastilbene (DAS). Time-resolved ESR spectra have been observed for the T_1 state of DAS in rigid glass and in stretched poly(vinyl alcohol) films using an excimer laser as an exciting light source. The results show that the geometry of the T_1 state DAS is nearly planar.
Time-resolved ESR spectra have been observed for the T_1 states of nitronaphtalenes. The observed lifetimes and zero-field splitting parameters show that is a strong vibronic coupling between the ^3 ^* and the close-lying ^3n^* states.
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