Kinetics and mechanism of the reaction of phenyl phenylmercury sulphide with picryl halides

Abstract

The rates of the reaction of phenyl phenylmercury sulphide with picryl halides to give phenyl 2,4,6-trinitrophenyl sulphide have been measured in various aprotic solvents (benzene, chlorinated hydrocarbons, nitromethane, dioxan, tetrahydrofuran, and acetone). The rate increases on passing from picryl chloride to bromide and to iodide. The reaction rate is only slightly affected by solvent change. Very large negative activation entropy values were found and there is a satisfactory linear relationship between ΔH^‡ and ΔS^‡. A four-centre, concerted mechanism is suggested for the reaction.