Synthesis of new cobalt–osmium mixed-metal clusters using a novel reactive cobalt species; X-ray crystal structure of [Os3Co(CO)10(C5Me4Et)H2]

Abstract

Thermal decomposition of the known complex [Co(C₅Me₄Et)(C₂H₄)Me₂] gives the intermediate species ‘Co(C₅Me₄Et)’ which reacts with [OS₃(CO)₁₀H₂] to produce [Os₃Co(CO)₁₀(C₅Me₄Et)H₂]. This complex crystallises in the triclinic space group P with a= 9.072(4), b= 10.477(5), c= 13.921(7)Å, α= 95.80(3), β= 93.54(3), γ= 102.48(3)°, and Z= 2. The structure was solved by a combination of direct methods and Fourier-difference techniques and refined by blocked-cascade least squares to R= 0.039 for 3 084 diffractometer data. The Co(C₅Me₄Et) fragment caps the Os₃ triangle. Each Os atom is also co-ordinated to three terminal carbonyl groups while the tenth carbonyl bridges an Os–Co bond. The complex [Os₃Co(CO)₁₀(C₅Me₄Et)H₂] reacts with hydrogen to give [Os₃Co(CO)₉(C₅Me₄Et)H₄], and both clusters react with carbon monoxide under fairly mild conditions to yield [Os₃(CO)₁₂] and [Co(CO)₂(C₅Me₄Et)].