Protodemercuration of organomercuric chlorides. I. Aromatic mercuric chlorides

Abstract

The kinetics of protodemercuration, or displacement of the HgCl group by hydrogen, have been measured for phenylmercuric chloride, and also for its meta and para methyl-, chloro-, and methoxy-substituted derivatives. The reactions of the compounds with aqueous alcoholic hydrochloric acid were first order in RHgC1, first order in hydrogen ion, and zero order in chloride ion. At 70" the relative rates, which were largely determined by entropy factors, were: phenyl, 1; p-tolyl, 7; m-tolyl, 2.4; p-chlorophenyl, 0.67; m-chlorophenyl, 0.26; p-methoxy, 150; m-methoxy, 0.71. A plot of log k against σ⁺ gives a ρ value of -2.44, and correlation coefficient of 0.986.