Synthesis and characterization of mixed ruthenium/platinum mu(4)-phosphinidene, phosphorus monoxide, and related clusters.

The mixed-metal cluster complexes [Ru(4)(CO)(12)Pt(CO)PPh(3)(mu(4)-PR)] [R = N(i)Pr(2) (1), F (3)] were formed by capping the Ru(3)P face of the nido clusters [Ru(4)(CO)(13)(mu(3)-PR)] with the labile Pt(0) reagent [(eta(2)-C(2)H(4))Pt(PPh(3))(2)]. The aminophosphinidene complex 1 undergoes acid hydrolysis to yield the PO complex [Ru(4)(CO)(12)Pt(CO)PPh(3)(mu(4)-PO)][H(2)N(i)Pr(2)] (4). The fluorophosphinidene cluster 3 reacts with ethanol to form the alkoxyphosphinidene complex [Ru(4)(CO)(12)Pt(CO)PPh(3)(mu(4)-POEt)] (5). Comparison of spectroscopic and structural data for clusters 1, 3, 4, and 5 reveals the remarkable effects of the mu(4)-phosphinidene and phosphorus monoxide ligands on cluster bonding.