Reaction of the diyne complex [Os 3(μ-CO)(CO) 9{μ 3-η 2-Me 3SiCCC [tbnd]CSiMe 3}] with phosphines and phosphites: Characterization of monophosphine substituted clusters [Os 3(μ-CO)(CO) 8(PR 3){μ 3-η 2-Me 3SiCCC [tbnd]CSiMe 3}] (PR 3 = PPh 3, P(OEt) 3, PEt 3, PHPh 2 and Ph 2PCH 2PPh 2)

Abstract

The reactions of [Os 3(μ-CO)(CO) 9{μ 3-η 2-Me 3SiCCC CSiMe 3}] with phosphorus donor ligands (PPh 3, PEt 3, P(OEt) 3, PHPh 2 and a diphosphine; Ph 2PCH 2PPh 2 (dppm)) afford carbonyl mono-substitution products [Os 3(μ-CO)(CO) 8(L){μ 3-η 2-Me 3SiC 2C 2SiMe 3}] even in the case of the bidentate phosphine dppm. All the complexes have been characterized by IR and multinuclear NMR spectroscopy and for 2 (L = PPh 3), 3 (L = PEt 3), 4 (L = P(OEt) 3) and 5 (L = η 1-dppm) the structures have been confirmed by single-crystal X-ray analysis. The structural analyses show that in all four clusters the substitution has occurred at one of osmium equatorial sites that is σ-bonded to the μ 3-η 2-alkyne.