作者:A.C. Testa
DOI:10.1016/s1386-1425(99)00192-4
日期:2000.4
Laser flash photolysis of the photocyclization of triphenylimidazole (TPI) in ethyl alcohol at 308 nm. indicates that the dihydrophenanthroimidazole (DHPI) intermediate is produced rapidly, has a lifetime of 0.25 ms, and returns predominantly back to triphenylimidazole. Analysis of the decay channels for this intermediate indicates two rate constants: (1) k1 = 3.3 x 10(3) s(-1), associated with reversion
激光闪光光解了308 nm下三苯基咪唑(TPI)在乙醇中的光环化。表示二氢菲并咪唑(DHPI)中间体生产迅速,寿命为0.25 ms,主要返回三苯基咪唑。分析该中间体的衰变通道表明两个速率常数:(1)k1 = 3.3 x 10(3)s(-1),与还原回三苯基咪唑有关;(2)k2 = 0.67 x 10(2)s( -1),这与二氢菲并咪唑向光产物2-苯基-9,10-菲并咪唑的转化有关。容易在双指数荧光衰减数据中观察到光产物作为增加的成分。三苯咪唑和2-苯基-9,10-菲基咪唑(PPI)在乙醇中的荧光寿命确定为1.76和8.21 ns,随着光化学的进行,荧光中没有其他成分会衰减。在450 nm处观察到额外的瞬态吸收。区域的寿命为0.7微米,其衰变速度比二氢菲并咪唑中间体快,被指定为三苯基咪唑的三重态。