Equilibria in complexes of N-heterocyclic molecules. XVII. Covalent hydration and the rate of dissociation of the Bis(2,2':6',2'-terpyridyl)iron(III) ion in acid solution

Abstract

The dissociation of Fe(tpy)₂³⁺ has been studied in aqueous sulfuric acid. The rate of reaction increases upon addition of small amounts of acid, reaches a maximum, and then falls to zero in a complex fashion as the acid approaches limiting concentration, and a_H2O falls to zero. No dissociation occurs in the absence of water, and it is evident that covalent hydration of the complex is an essential step in the dissociation process.