Characterization of the nucleophilic reactivities of thiocarboxylate, dithiocarbonate and dithiocarbamate anions
作者:Xin-Hua Duan、Biplab Maji、Herbert Mayr
DOI:10.1039/c1ob06245j
日期:——
The kinetics of the reactions of thiocarboxylate and thiocarbonate anions with benzhydrylium ions have been determined in acetonitrile solution using laser-flash photolytic techniques. The second-order rate constants (k) correlate linearly with the electrophilicity parameters E of the benzhydrylium ions, as required by the correlation log k (20 °C) = sN(N + E) (J. Am. Chem. Soc., 2001, 123, 9500–9512), allowing us to calculate the nucleophile-specific parameters N and sN for these anions. With these parameters, a direct comparison of the reactivities of thiocarboxylate, dithiocarbonate and dithiocarbamate anions with other nucleophiles becomes possible.
运用激光闪光光解技术,在乙腈溶液中测定了硫羧酸根和硫碳酸根离子与苯并二氢吡喃离子反应的动力学。二级速率常数(k)与苯并二氢吡喃离子的亲电参数 E 呈线性相关,符合关系式 log k(20 °C)= sN(N + E)(J. Am. Chem. Soc., 2001, 123, 9500–9512),从而能够计算出这些阴离子的亲核体特异性参数 N 和 sN。有了这些参数,就可以直接比较硫羧酸根、二硫代碳酸根和二硫代氨基甲酸根离子与其他亲核体的反应活性。