1992 Fiscal Year Final Research Report Summary
Studies on Reaction Dynamics and Molecular Dynamics of Para magnetic Intermediates by Use of Pulsed FT-ESR Method
| Project/Area Number |
02403003
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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 | Osaka University |
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Principal Investigator |
KUWATA Keiji Osaka University,Faculty of Science,Professor, 理学部, 教授 (50028099)
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| Co-Investigator(Kenkyū-buntansha) |
MURAI Hisao Osaka University,Faculty of Science,Research Instructor, 理学部, 助手 (50142261)
KAMACHI Mikiharu Osaka University,Faculty of Science,Professor, 理学部, 教授 (40028163)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Pulsed FT-ESR / Para magnetic Intermediate / Process of Reaction Dynamics / Process of Molecular Dynamics / Short-Lived Reaction Intermediate / Electron Spin Relaxation / Dynamic Spin Polarization / ラジカル対 |
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| Research Abstract |
By use of a pulsed FT-ESR spectrometer, which has been built in 1990 for the studies on reaction dynamics and molecular dynamics of the short-lived free radical intermediates in chemical reaction, the intermediate states and the spin dynamics of photo reduction and photoxidation were investigated in 1992. And also studies on chemical kinetics of the initiation step of photo polymerization were carried out. 1) Time-resolved ESR studies of chemically induced electron spin polarization (CIDEP) in photosensitized reduction of maleic anhydride gave a new finding that the spin polarization is caused by ST-1 mixing in a geminate radical ion pair in the photoinduced electron transfer reaction. On the basis of the results of the studies on spin polarization in the systems with different donors and solvents reaction mechanisms were discussed in detail. 2) The structure and the reaction rates with vinyl monomers of the reactive fragments of several photoinitiators of polymerization were determine
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d. And the direct observation of the initiating radicals in photopolymerization was firstly succeeded. 3) A quasi-stable spin-correlated radical pair in an micellar system was investigated by time-resolved ESR spectroscopy. For the analysis of the external magnetic field effect on the decay rates of the radical pair stochastic Liouville calculation was carried out. 4) In the photoreaction of benzophenone in an alcoholic solution the electron spin relaxation processes of the short-lived intermediates in the reaction were investigated by pulsed FT-ESR spectroscopy. In this investigation new findings on the spin dynamics and reaction mechanisms were obtained. 5) The electron transfer reaction of the negative ions of p-quinone derivatives with neutral molecules and the electron spin exchange reaction between negative ions were investigated by pulsed FT-ESR spectroscopy in detail. The results of these investigations show the usefulness of pulsed FT-ESR spectroscopy for the investigation of molecular dynamics of short-lived reaction intermediates. Less
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