Development of Highly Time-resolved High Frequency EPR and Application to Studies on the Excited States

为EPR装置的构建及其研究应用取得了以下结果。为了提高W波段EPR系统的时间分辨率，我们购买了一个宽带放大器，将阻抗匹配到2000，实现了小于5纳秒的时间分辨率，降低了信号的损耗。我们将这台高频EPR机器应用于激发态多重态的研究，得到了激发态动力学和自旋弛豫的数据。我们还首次在热平衡条件下获得了激发三重态-自由基体系多重态的EPR信号。根据多重态和交换相互作用参数J.4之间的能量差更容易分析这样的光谱。利用上述(在热平衡条件下)得到的数据，可以很容易地从激发态动力学和自旋驰豫的角度来分析极化光谱。利用这些数据(多重态之间的能量差、交换相互作用参数J、激发态动力学和自旋弛豫)，我们成功地减去了决定两个不同异构体自由基激发的三重态系统激发态性质的重要因素。

The following results were obtained for the construction of the EPR apparatus and its research applications.1. In order to increase time-resolution of the W-band EPR system, we bought a wide band amplifier, made impedance matching to 2000, and achieved a time resolution of less than 5 nano-seconds and a decrease of the loss of the signals.2. We applied this high frequency EPR machine to the studies of excited multiplet states and obtained data of excited state dynamics and spin relaxations.3. We also obtained EPR signals for the first time under a thermal equilibrium condition in the excited multiplet states of an excited triplet-radical system. Such spectra were more easily analyzed in terms of an energy difference between the multiplet states and an exchange interaction parameter J.4. The polarized spectra are now easily analyzed by using the data obtained above (under a thermal equilibrium condition) in terms of excited state dynamics and spin relaxations.5. With these data (an energy difference between the multiplet states, an exchange interaction parameter J, excited state dynamics, and spin relaxations), we succeeded in subtracting important factors which determine excited state properties in two different isomer radicals-excited triplet systems.