Advanced investigations on a methodology called election-transfer sapped flow method

在本项目中，作为电子转移停流法的进一步研究，我们分析了短寿命芳香族阳离子自由基在乙腈中的反应。对于苯甲胺和N-甲基苯甲胺阳离子自由基的反应，发现反应机理发生了变化，反应活性也发生了变化。此外，电子转移停流法还揭示了取代基对苯胺衍生物阳离子自由基反应中间位和邻位的影响，以及噻吩衍生物中二聚阳离子自由基和三聚阳离子自由基反应活性的差异。针对前者，对乙腈中的间氯、甲基和甲氧基取代的二苯胺阳离子自由基进行了系统的研究。从动力学角度阐明了三芳胺衍生物分子存在阳离子自由基-阳离子自由基偶联反应和依赖于取代基的单一阳离子自由基的环化反应两种类型的连续反应，并用电子转移停止流方法测量了阳离子自由基和三芳胺衍生物分子的时间分辨可见吸收光谱，提供了与取代基和分子结构有关的反应活性和稳定性的信息。结果发现，一些体积较大的取代基对阳离子的反应活性有显著影响。此外，还研究了胺基有机高自旋体系氧化态的电光性质。

In this project, as the advanced investigations of the electron-transfer stopped flow method, we analyzed the reactions of short lived aromatic cation radicals in acetonitrile. For the reactions of anisidine and N-methyl anisidine cation radicals, it was found that the reaction mechanism changed as well as the reactivity. In addition, the electron-transfer stopped-flow method was revealed the effects of the substituents on the meta-and ortho- positions in the reactions of aniline derivative cation radicals and the differences in the reactivity of the dimmer and trimer cation radicals of thiophene derivative. In relation with the former case, systematic investigations were performed for the meta- chloro-, methyl- and methoxy-substituted diphenylamine cation radicals in acetonitrile. As the result, it was clarified from the kinetic view point that there are the two types of the consecutive reactions, i.e., the cation radical-cation radical coupling reaction and to the cyclization reaction of single cation radical depending on the substituents.Furthermore, the electron-transfer stopped flow method was applied to the measurement of the time-resolved visible absorption spectra of the cation radicals and dications of triarylamine derivative molecules, which should give information about the, reactivity and the stability depending on the substituents and molecular structures. Consequently, some bulky substituents were found to affect the reactivities of the di cations significantly. In addition, the electronic optical properties of the oxidized states of amine-based organic high-spin systems were investigated.