Photosensitized Reduction of Sulfonium Salts: Evidence for Nondissociative Electron Transfer
作者:Xiuzhi Wang、Franklin D. Saeva、J. A. Kampmeier
DOI:10.1021/ja982932x
日期:1999.5.1
The photosensitized reductions of 4-cyanobenzylmethylphenyl sulfonium tetrafluoroborate (1-BF4) by 9-phenylanthracene, 2-ethyl-9,10-dimethoxyanthracene, or perylene excited singlet states gives quantitative yields of phenyl methyl sulfide. Fluorescence quenching and the quantum yields for product formation, as functions of [1-BF4], give bimolecular rate constants (0.58−1.6 × 1010 M-1 s-1) for reaction
4-氰基苄基甲基苯基锍四氟硼酸盐 (1-BF4) 被 9-苯基蒽、2-乙基-9,10-二甲氧基蒽或苝激发的单线态光敏还原给出了苯基甲基硫醚的定量收率。荧光猝灭和产物形成的量子产率作为 [1-BF4] 的函数,给出了激发敏化剂与锍盐反应的双分子速率常数 (0.58−1.6 × 1010 M-1 s-1)。对于三种敏化剂,对应于无限 [1-BF4] 的极限量子产率为 0.65-0.77,表明光还原效率显着低下。这些低效率归因于硫酰基自由基中间体在两步缔合电子转移机制中的分配。