Kinetics of the oxidation of water by silver(II) ions complexed with 2,2′-bipyridine in aqueous nitrate media

The kinetics of the oxidative decay of silver(II) ions complexed by 2,2′-bipyridine (bipy) when present in aqueous acidic media have been investigated. The reaction is found to be second order in [AgII] and zero order in [H+] with an inverse dependence on [AgI]. From a detailed consideration of the experimental data, including the overall enthalpy and entropy of activation, it is concluded that AgIII is not involved as an intermediate and that the essential redox step consists of the interaction of two molecules of [Ag(bipy)(OH)]+ formed in the hydrolysis of [Ag(bipy)]2+(aq), which has been found to be the active bipy complex of AgII involved in the oxidation of substrate ligands added to aqueous solutions.