Syntheses and reactions of some cluster complexes containing C4ligands with iron, ruthenium and cobalt carbonyls

Abstract

Some reactions of W(CCCCH)(CO)₃Cp with metal cluster carbonyls have been studied. With Ru₃(CO)₁₀(NCMe)₂ the initial product is Ru₃{μ₃-HC₂CC[W(CO)₃Cp]}(μ-CO)(CO)₉, which readily transforms into Ru₃(μ-H){μ₃-C₂CC[W(CO)₃Cp]}(CO)₉. Similar chemistry is found with the dppm analogue: three interconverting isomers of Ru₃(μ-H){μ₃-C₂CC[W(CO)₃Cp]}(μ-dppm)(CO)₇ can be detected in solution. Reactions of Ru₃(μ-H){μ₃-C₂CC[W(CO)₃Cp]}(CO)₉ with Ru₃(CO)₁₂ afforded {Ru₃(μ-H)(CO)₉}(μ₃-η²∶μ₃-η²-C₂C₂){Ru₂W(CO)₈Cp}, while Fe₂(CO)₉ gave an analogous product in which three of the ruthenium sites are partially occupied by a total of one or two iron atoms; with Co₂(CO)₈ the vinylidene cluster {CoRu₂(CO)₉}(μ₃-η²∶μ₃-η²-CCHC₂){CoRuW(CO)₈Cp} was formed, the cluster-bound hydride transferring to the C₄ ligand. The molecular structures of five complexes have been determined by single-crystal X-ray studies. Theoretical calculations have rationalised the tendency for the formation of μ₃-η²-C₂ fragments in these C₄ clusters.