Reactions of the Cluster Anion [HRu3(CO)11)]− with Dicyclohexylphosphine: Synthesis and Molecular Structure of H2Ru3(CO)8(PCy2)2 and H2Ru3(CO)6(PCy2)2(HPCy2)2

Abstract

The cluster anion [HRu3(CO)11]- (1) reacts with dicyclohexylphosphine in THF solution to give the anionic derivative [HRu3(CO)8(PCy2)2]- (2), protonation of which yields the neutral cluster H2Ru3(CO)8(PCy2)2 (3) and, in the presence of excess phosphine, HRu3(CO)7(PCy2)3 (4). In protic methanol as reaction medium, the reaction of 1 with HPCy2 gives directly the neutral complex H2Ru3(CO)6(PCy2)2(HPCy2)2 (5), together with 4. The single-crystal structure X-ray analysis of 3 shows a closed triangular Ru3 framework. The electron count is in accordance with the EAN rule, but the structure analysis of 5 reveals an open, almost linear Ru3 skeleton, which is electron-deficient with respect to the EAN rule.