Catalytic Activation of Molecular Hydrogen by Ruthenium (Iii) Chloride Complexes

Ruthenium(III) chloride, in aqueous HCl solution, was found to activate H 2 homogeneously and to catalyze the reduction by H 2 of Ru(IV)and Fe(III). The kinetics of these reactions were examined and, in each case, the rate law was found to be −d[H 2 ]/dt = k 1 [H 2 ][Ru III ] where k 1 = 4.0 × 10 14 exp [−23,800/RT] M −1 sec −1 . The mechanisms of these reactions are discussed and compared to those of other homogeneously catalyzed reactions of hydrogen. A special feature of the present system is the resistance of the catalytic species itself (i.e. Ru III ) to reduction by H 2 .