High nuclearity ruthenium carbonyl cluster chemistry IV ¹. Reactivity of [Ru₁₀(μ-H)(μ₆-C)(CO)₂₄]^- towards trimethylphosphite or bis(diphenylphosphino) acetylene; X-ray crystal structure of PPh₄[Ru₁₀(μ-H)(μ₆-C)(CO) ₂₂{P(OMe)₃}₂]

Abstract

Reaction of [PPh4][Ru10(μ,-H)(μ6-C)(CO)24] (1a) with two equivalents of trimethylphosphite at room temperature gives a mixture of the mono-(2a), bis-(3a), tris-(4a) and tetrakis-(5a) phosphite-substituted cluster anions [Ru10(μ-H)(μ6-C)(CO)24-x{P(OMe)3}x]- (x = 1-4). Reaction of [Ru2(μ-H)(μ-NC5H4)2(CO)4(NC5H5)2][Ru10(μ-H)(μ6-C)(CO)24] (1b) with ten equivalents of trimethylphosphite at room temperature gives the tetrakis-substituted anion [Ru10(μ-H)(μ6-C)(CO)20{P(OMe)3}4]- as its [Ru2(μ-H)(μ-NC5H4)2(CO)4{P(OMe)3}2]+ salt (5c). Cluster 3a has been characterized by an X-ray structural study, which confirms that the phosphite ligands occupy apical sites in these clusters. Reaction of [Ru10(μ-H)(μ6-C)(CO)24]- with 20 equivalents of trimethylphosphite in refluxing acetone leads to tetradecapping of the decaruthenium core and formation of Ru6(μ6-C)(CO)13{P(OMe)3}4 (6). Reaction of 1b with 0.5 equivalents of bis(diphenylphosphino)acetylene gives the linked icosaruthenium cluster dianion [{Ru10(μ-H)(μ6-C)(CO)23}2(μ-Ph2PC≡CPPh2)]2- (7b); heating 7b leads to loss of the phosphine rather than ligand-assisted condensation.