Influence of electrolytic dissociation upon rates of reactions. Part V. Retardation of base hydrolyses of halogenopenta-amminecobalt(III) ions by anions

Abstract

The base hydrolysis rates of chloro-, bromo-, and iodo-penta-amminecobalt(III) at 25° are retarded by sulphate and several dicarboxylates. This is ascribed to ion-paring. The effects are generally related to the ion-pair dissociation constants and the retardations decrease with increasing halide size for a particular ligand. Some evidence is cited to support a recent assertion that Chan's claim, that there is kinetic evidence of significant complex ion–hydroxide ion-pairing, is untrue.