1987 Fiscal Year Final Research Report Summary
Kinetic Studies on the Reaction of Pyridinyl Radicals byMeans of Time-Resolved Magnetic Resonance Spectroscopy
| Project/Area Number |
60430001
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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 | TOHOKU UNIVERSITY |
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Principal Investigator |
IKEGAMI Yusaku Chemical Research Institute of Non-Aqueous Solutions, Tohoku University, Professor, 排水溶液科学研究所, 教授 (60006294)
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| Co-Investigator(Kenkyū-buntansha) |
TERO Shozo Chemical Research Institute of Non-Aqueous Solutions, Tohoku Universiry, Associa, 非水溶液科学研究所, 助教授 (80111318)
AKIYAMA Kimio Chemical Research Institute of Non-Aqueous Solutions, Tohoku University, Assista, 排水溶液科学研究所, 助手 (10167851)
ONODERA Shinji Chemical Research Institute of Non-Aqueous Solutions, Tohoku University, Associa, 排水溶液科学研究所, 助教授 (30006316)
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| Project Period (FY) |
1985 – 1987
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| Keywords | time-resolved ESR / ESR / CIDEP / pyridinyl radical / diradical / kinetic ESR / spin polarization / エネルギーの移動 |
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| Research Abstract |
Kinetic studies for the convertible monomer-dimer systems of pyridinyl radicals have been carried out.
1. ESR and NMR spectrometer systems were fully equipped for the detection of chemically induced electron and nuclear spin polarization (CIDEP and CIDNP) phenomena.
2. Kinetic parameters for the dimerization of various pyridinyl radicals were determined by the use of a kinetic ESR systems. The dimerization mechanisms with and without intervension of intermediate were discussed.
3. The CIDEP studies on the photochemical cleavage of pyridinyl radical dimers elcuidated that the radicals are generally produced through the singlet radical pair precursor, since an A(absorption)/E(emission) pattern was exhibited in the transient ESR spectra.
4. A spin polarization conservation during excitation energy transfer in solution was firstly observed in the CIDEP measurements for the photodissociation of the 1-methyl-4-alkylpyridinyl radical dimers in the presence of triplet sensitizers. This suggests a possibility of the dimer photodissociation from the triplet state.
5. The 1,1'-ethylenebis- and 1,1'-trimethylenebis-(pyridinyl) diradicals exist as the diamagnetic cyclomers of dl and meso forms at room temperature. Both forms photodissociate to generate the diradical, which can be detected at 77 K.
6. Application of time-resolved ESR measurement to some organic photoreactions led to exciting results in the detection of intermediates.
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