1998 Fiscal Year Final Research Report Summary
A Study of Excited -State-Proton-Transfer Reaction
| Project/Area Number |
09640610
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Ehime University |
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Principal Investigator |
NAGAOKA Shin-ichi Ehime University, Faculty of Science, Associate Professor, 理学部, 助教授 (30164403)
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| Co-Investigator(Kenkyū-buntansha) |
OHARA Keishi Ehime University, Faculty of Science, Assistant, 理学部, 助手 (10284390)
MUKAI Kazuo Ehime University, Faculty of Science, Professor, 理学部, 教授 (70036193)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Excited State / Proton Transfer / Salicylaldehyde / Vitamin E / Excited-State Dependence / Node / Intramolecular Hydrogen Bond / Antioxidant Reaction |
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| Research Abstract |
Proton transfer is a very simple chemical process readily accessible to both accurate measurement and quantitative theoretical analysis. We have constructed a simple theoretical model of the excited-state-proton-transfer, a model based on the nodal pattern of the wave function. In this project we have studied the application of our nodal-plane model to the following three problems.
1. The substituent effect and the electronic-state dependence in the excited-state-intramolecular-proton-transfer (ESIPT) of o-hydroxybenzladehydes.
2. The substituent-position effect in ESIPT of 2-(o-hydroxyaryl)benzazoles : Although both 2-(2-hydroxy- 3-aryl)benzazole and 2-(1-hydroxy- 2-aryl)benzazole consist of an aryl moiety, a benzazol-2-yl group, and an Oil group, their emission properties are very different.
3. The substituent and solvent effects in ESIPT of aminoanthraquinones : The singlet-triplet energy-gap of the proton-transferred form is much less than that in the normal form.
The experimental results obtained on the above three problems strongly support our nodal-plane model.
Furthermore, we synthesized a bridged molecule of vitamin E and quinones, and studied the radical scavenging reaction of vitamin E.It is interesting that the microscopic electron behavior could manifest itself in the macroscopic vital-function.
Although our nodal-plane model is a qualitative one, it allows us to recognize the important features of ESIPT immediately and provides useful information about the reaction mechanisms. Our nodal-plane model is applicable to photochemical reactions in various excited states of various molecules. Many chemists have cited it, and the usefulness of our explanation is recognized by many researchers.
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