Catalytic Activation of Molecular Hydrogen by Ruthenium Chloride Complexes in N,N-Dimethylacetamide Solution

Abstract

N, N-Dimethylacetamide solutions of "RuCl3•3H2O", which is a mixture of Ru (IV) and Ru(III), react with hydrogen under mild conditions in stepwise stoichiometric processes to give finally univalent species [Formula: see text]. Reactions 1 and 2 involve heterolytic activation of H2 by a Ru III catalyst and likely proceed via a RuIIIH intermediate; the same catalyst catalyzes the hydrogenolysis of oxygen to water. Reaction 3 involves a RuIIH intermediate. Kinetic parameters are presented for processes 1–3 and the catalytic water production, and are compared with data for some systems that have been studied previously in aqueous acid chloride solutions. Reactions 1 and 2 occur much more readily in the non-aqueous solvent due to a lower activation energy, while reaction 3 occurs only in the non-aqueous system. A detailed interpretation of the data is limited by the uncertain nature of species present in the amide solvent.