Evaluation of Ultrafast Intramolecular Electron Transfer Rate by Means of NMR Relaxation
| Project/Area Number |
08454235
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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 |
分離・精製・検出法
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| Research Institution | Ochanomizu University |
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Principal Investigator |
MASUDA Yuichi Faculty of Science, Ochanomizu University, Professor, 理学部, 教授 (20181654)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1998: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1996: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | spin-lattice relaxation / solvation dynamics / intramolecular electron transfer / スピン-格子緩和 |
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| Research Abstract |
The intramolecular electron transfer rates in solution were evaluated in several systems by NMR spin-lattice relaxation measurements. A limitation of this method was confirmed referring the rotational relaxation time and the electron spin relaxation time, etc.
The reaction rates with pico second order were observed for three mixed-valence biferrocene derivatives (Fe(II), Fe(III)) and the rates showed a characteristic behavior. The biferrocene monocation showed ca. three times larger rate constant than its 1,1 "'- diiodo derivative, nevertheless these two mixed-valence compounds show similar intervalence band energy and strength. This results can be attributed to difference in the ratio of the outersphere and the innersphere reorganization energy. The frequency difference in the L-M-L stretching modes is another reason of the retardation of the ET rate of diiodo derivatives, On the other hand, an acetylene bridged biferrocene monocation gave three times higher rates than those boferrocene monocation. This result is disagreement with the IT band measurements. The temperature dependence of the rate of the acetylene bridged complex suggested considerable nuclear tunneling effect on the rates. This may be arisen by the rigid bridging structure of the mixed-valence complex.
All the rates given in the present studies exceed those predicted any model including solvent dynamical effect as long as solvent is regarded as a dielectric continuum. Faster local solvent dynamics may be, at least partially, responsible to control the rates.
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Report
(4 results)
Research Products
(15 results)
