Flash Photolytic Generation of a Dithio Carbocation from 1,3-Dithiolane Derivatives and Its Reaction with Nucleophiles
作者:Tadashi Okuyama、Naoki Haga、Shin-ya Takane、Kenji Ueno、Takayuki Fueno
DOI:10.1246/bcsj.64.2751
日期:1991.9
2-Phenyl-1,3-dithiolanylium ion is generated as a transient intermediate by flash photolysis of aqueous ethanol and acetonitrile solutions of 2-methoxy and other dithiolane derivatives with a xenon lamp. Decay of the absorption (342 nm) of the cation generated from the 2-methoxy derivative follows pseudo-first-order kinetics. Rate constants were measured for the reaction of the cation with various nucleophiles. Decay curves for the cations generated from 2-arylthio and 2-sulfonyl derivatives are steep and show second-order kinetic character owing to the recombination of the cation with the counter anions (thiolate and sulfinate).
用氙灯对 2-甲氧基和其他二硫环戊烷衍生物的乙醇和乙腈水溶液进行闪烁光解,生成瞬时中间体 2-苯基-1,3-二硫环戊烷离子。由 2-甲氧基衍生物生成的阳离子的吸收(342 纳米)衰减遵循伪一阶动力学。测量了阳离子与各种亲核物反应的速率常数。由 2-芳硫基和 2-磺酰基衍生物生成的阳离子的衰减曲线很陡,显示出二阶动力学特征,这是由于阳离子与反阴离子(硫酸盐和亚硫酸盐)发生了重组。