Characterization of the nucleophilic reactivities of thiocarboxylate, dithiocarbonate and dithiocarbamate anions

Abstract

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) = s_N(N + E) (J. Am. Chem. Soc., 2001, 123, 9500–9512), allowing us to calculate the nucleophile-specific parameters N and s_N for these anions. With these parameters, a direct comparison of the reactivities of thiocarboxylate, dithiocarbonate and dithiocarbamate anions with other nucleophiles becomes possible.