Kinetics of the reactions of picryl chloride with substituted benzoate ions

Abstract

Second-order rate constants have been measured for the reactions of picryl chloride with substituted benzoate ions in 80% methanol–water at several temperatures, and activation parameters have been calculated. The results are compared with corresponding data for the reactions of picryl chloride with anilines and phenoxide ions. For the meta- and para-substituted compounds a plot of log k against σ gave ρ–1·05 (r 0·965). From a Brönsted-type correlation involving the pK_a values of the corresponding benzoic acids β= 0·70. A linear relationship between ΔH and ΔS is indicative of a single mechanism.