KINETICS OF OXIDATION OF ANILINE AND XYLIDINES BY THE TETRAHYDROXOARGENTATE(III) ION

The reactions of [Ag(OH)4]- with aniline and xylidines have been investigated. The stopped-flow experiments reveal kinetically distinguishable steps involving initial complexation of the substrate with the silver(III) species which is followed by its decomposition. The latter process obeys first-order kinetics and takes place with a rate constant of about 0.8 s-1 through intramolecular electron transfer from substrate to the silver(III) center. Azobenzene and p-benzoquinone have been identified as the main products of the reaction of [Ag(OH)4]- and aniline. An increase in concentration of aniline enhances the yield of azobenzene which accounts for approximately 65% of the consumed aniline. This effect has been interpreted by the increased effective complexation between aniline and [Ag(OH)4]- at higher concentrations. The stoichiometry of the reaction is found to vary with a change in the concentration of aniline. At higher concentrations it comes out to be 1:2 for [Ag(OH)4]-:aniline. A mechanism of this reaction is worked out.