1993 Fiscal Year Final Research Report Summary
Highly Sensitive TM-mode ENDOR and its Biological Applications
| Project/Area Number |
04640443
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
YAMAUCHI Jun Kyoto University, Graduate School of Human & Environmental Studies, Prof., 大学院・人間・環境学研究科, 教授 (10027071)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIMOTO Toyonari Kyoto University, Graduate School of Engineering, Associate Prof., 大学院・工学研究科, 助教授 (30093256)
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| Project Period (FY) |
1992 – 1993
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| Keywords | ENDOR / TM-mode cavity / flat ESR cell / sterical hindrance / NO scavenger / Wurster's blue cation radical / nitroxide radical / benzophenone anion radical |
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| Research Abstract |
In order to accomplish a high sensitive ENDOR spectrometer and its development into biological systems, we examined electronis circuits and a cavity therein. In particular, a TM mode-type ENDOR cavity was precisely checked and newly produced by repeating actual observations using several of the typical organic radicals. We finally obtained high loaded Q-value amounting to more than 3000, which essentially contributes ro the high sensitivity and low signal-to-noise ratio.
Systems investigated were sterically hindeered 2-methylbenzophenone anion radical, nitric oxide (NO) scavebger 4,4,5,5-tetramethyl imidazoline-1,3-oxyl, Wurster's blue cation radical and so forth. In the sterically hindered system, there are lot of non-equivalent protons resulting in broad ESR lines. In our case we could resolve 8-9 lines which allowed perfect ESR analysis, and a hindered rotation mechanism was discussed in detail. ^1H- and ^<14>N-ENDOR spectra of NO-trapping scavenger revealed an important role of NO in the biological systems. In addition, it was established that a flat cell combined with the TM-mode cavity is powerful to study the biological important radicals, which sometimes cause low Q-value and therefore low sensitivity in ENDOR.
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