Oxidative addition reactions of triphenylphosphine with dodecacarbonyltriosmium

Abstract

Reaction of Os₃(CO)₁₂ with PPh₃ in the mole ratio of 1 : 2 gave a mixture of nine products among which were the unusual new compounds HOs₃(CO)₉(PPh₃)(PPh₂C₆H₄), HOs₃(CO)₈(PPh₃)(PPh₂C₆H₄), HOs₃(CO)₇(PPh₂)(PPh₃)(C₆H₄), Os₃(CO)₈(PPh₂)(Ph)(PPhC₆H₄), and Os₃(CO)₇(PPh₂)₂(C₆H₄). Decomposition of Os₃(CO)₁₀(PPh₃)₂ led to a similar mixture which also included the compound HOs₃(CO)₇(PPh₂)(PPh₂C₆H₄C₆H₃). Some analogous AsPh₃ and P(C₆H₄Me)₃ derivatives and the new protonated species [HOs₃(CO)₉(PPh₃)₃]⁺Br^– were also prepared, the latter to assist in n.m.r. studies. The general properties, structures, and i.r., high field n.m.r., and mass spectra of the new compounds are described.