Mechanisms of carbazole photoluminescence quenching by the free and chemically bound nitroxyl radicals in the model bound system “carbazole (CBZ)—imidazolidine nitroxyl radical R•” were investigated and the photophysical properties of the system were studied and compared with those of free CBZ and R• in solution. The quantum yield and lifetime of fluorescence from the local singlet excited state of
研究了模型结合体系“
咔唑(C
BZ)-
咪唑烷
硝酰基自由基R•”中游离和
化学结合的
硝酰基自由基对
咔唑光致发光猝灭的机理,研究了该体系的光物理性质并与游离C
BZ和R的光物理性质进行了比较• 在溶液中。结合C
BZ-R• 系统中
咔唑部分的局部单线激发态荧光的量子产率和寿命比游离C
BZ 低三个数量级。结合系统中
咔唑部分的局部三重激发态的寿命短于 50 ns。发现
乙腈中R•对游离C
BZ的单重激发态和三重激发态的分子间猝灭速率常数分别为(1.4±0.1)·1010和(1.5±0.2)·109 L mol-1 s-1。