HYDROGEN ACTIVATION BY ARENE-RUTHENIUM COMPLEXES IN AQUEOUS-SOLUTION .3. SYNTHESIS OF HETEROMETALLIC RUTHENIUM-RHODIUM HYDRIDE COMPLEXES

The low pressure hydrogenation of the hydrolysis mixture of (eta(6)-C6H6)(2)Ru2Cl4 in water leads, after removal of chloride by silver carboxylates, to the formation of dinuclear hydride complexes of the type [Ru-2(eta(6)-C6H6)(2)(mu(2)-H)(mu(2)-OH)(mu(2)-eta(2)-O(2)CR)](+). Analogously, the treatment of a mixture of (eta(6)-C6H6)(2)Ru2Cl4 and (eta(6)-C(5)Me(5))(2)Rh2Cl4 with silver carboxylates and subsequent hydrogenation affords the mixed-metal monohydrido complexes [(eta(6)-C6H6)Ru(mu(2)-H)(mu(2)-OH)(mu(2)-eta(2)-O(2)CR)Rh(eta(5)-C(5)Me(5))](+), containing two metal atoms in a chiral environment. The use of alpha-hydroxycarboxylates for this reaction causes the formation of the dihydrido complexes [(eta(6)-C6H6)Ru(mu(2)-H)(2){mu(2)-eta(2)-O2CCH(OH)R}Rh(eta(5)-C(5)Me(5))](+). The X-ray structure analyses of [Ru-2(eta(6)-C6H6)(2)(mu(2)-H)(mu(2)-H)(mu(2)-OH)(mu(2)-eta(2)-O(2)CMe)][ClO4] and [(eta(6)-C6H6>Ru(mu(2)-H)(2){mu(2)-eta(2)-(S)-O2CCH(OH)C6H5}Rh(eta(5)-C(5)Me(5))][ClO4] are reported.