Oxidative addition of 1,3-diynes at triosmium clusters with cleavage of the central carbon–carbon bond: X-ray crystal structure of [Os3(µ3,η2-C2Ph)(µ-C2Ph)(CO)9] derived from 1,4-diphenylbuta-1,3-diyne

Abstract

The diyne clusters [Os₃(µ₃,η²-RCCCCR)(CO)₁₀](R = Me, Et, Ph, Bu^t, SiMe₃) in hydrocarbon solvent at 120 °C decarbonylate to give the nonacarbonyl clusters [Os₃(µ₃,η²-C₂R)(µ-C₂R)(CO)₉] when R = Ph, Bu^t, or SiMe₃, [Os₃H(µ₃,σ,η²,η²-EtCC–CCCHMe)(CO)₉] when R = Et, and [Os₃(C₄Me₂)(CO)₉] of known structure when R = Me; the µ-C₂Ph ligand in [Os₃(µ₃, η²-C₂Ph)(µ-C₂Ph)(CO)₉](X-ray structure) is unusual in bridging unsymmetrically through only one carbon atom.