CH and CC bond activations of terminal alkynes in the presence of a butterfly-shaped heteronuclear Ru3Au cluster

The reaction of compound [Ru3(CO)10(?Cl)(?AuPPh3)] (1) with terminal alkynes HCtriple bond; length of mdashCR; (R = C6H44CH3, C6H32,5(CH3)2, C6H22,4,5(CH3)3, C(CH3) = CH2, Si(CH3)3), under very mild conditions yielded isostructural compounds [Ru3(CO)9(?AuPPh3)(?3?2?Ctriple bond; length of mdashCR)] (R = C6H44CH3 (2), C6H32,5(CH3)2 (3), C6H22,4,5(CH3)3 (4), C(CH3)double bond; length as m-dashCH2 (5), Si(CH3)3) (6)) respectively; where the alkynes suffer oxidative additions to the metallic fragment coordinating as acetylide groups in a ?3?2perpendicular fashion by breaking the C(sp)H bond of the alkynes. The AuPPh3 fragment remains without change in all compounds. All of these clusters have been characterized in solution by i.r. and n.m.r. spectroscopy and their structures have been established by single crystal Xray diffraction studies.