|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1993 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1992 : ¥1,500,000 (Direct Cost : ¥1,500,000)
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.