A study of the transients observed in the pulse radiolysis of aqueous solutions of aromatic organomercury compounds

Abstract

The reduction of aqueous solutions containing organomercury compounds by the hydrated electron has been studied by pulse and steady state radiolysis methods. The compounds have the general formula YC 6H 4HgX where Y is a carboxyl or hydroxyl group and X is a chlorine atom or a hydroxyl group. All of the compounds react with the hydrated electron by a diffusion controlled reaction to produce an Hg 1 intermediate that absorbs in the region 280–380 nm. The intermediates of all of the compounds disappear by a rapid first order process that have a rate constant on the order of 10 5 s -1. Time resolved and steady state electron spin resonance experiments on irradiated aqueous solutions of p-hydroxy-mercuribenzoic acid indicate that the carboxyphenyl radical is formed and this radical disappears by reaction with t-butyl alcohol. Analysis of the irradiated solutions by high performance liquid chromatography show that the carbon-mercury bond is broken in the reduction process. In the case of p-hydroxymercuribenzoic acid and o-hydroxymercuribenzoic acid the reaction product is benzoic acid.