Reactions of α-phenylethynyl-trans-β-styryl complexes with isonitriles: hemi-labile alkyne coordination

Treatment of the complex [Ru{C(C = CPh) = CHPh}Cl(CO)(PPh3)2] (1) with one equivalent of CNR (R = (t)Bu, C6H3Me2-2,6) gives [Ru{C(C = CPh) = CHPh}Cl(CNR)(CO)(PPh3)2]. Addition of a further equivalent of isonitrile and [NH4]PF6 leads to the salts [Ru{C(C = CPh) = CHPh}Cl(CNR)2(CO)(PPh3)2]PF6 and the mixed species [Ru{C(C = CPh) = CHPh}(CO)(CN(t)Bu)(CNC6H3Me2-2,6)(PPh3)2]PF6. The related [Ru{C(C = CPh)=CHPh}(CN(t)Bu)(CO)2(PPh3)2]PF6 is obtained by successive treatment of [Ru(CO)2(PPh3)3] with diphenylbutadiyne, hexafluorophosphoric acid and isonitrile or of 1 with carbon monoxide, AgPF6, and CN(t)Bu.