sigma-Organyl complexes of ruthenium and osmium supported by a mixed-donor ligand

A series of vinyl, aryl, acetylide and silyl complexes [Ru(R)(kappa(2)-MI)(CO)(PPh3)(2)] (R = CH=CH2, CH=CHPh, CH=CHC6H4CH3-4, CH=(CHBu)-Bu-t, CH=CHCPh2OH, (C=CPh)=CHPh, C6H5, C=CPh, SiMe2OEt; MI = 1-methylimidazole-2-thiolate) were prepared from either [Ru(R)Cl(CO)(PPh3)(2)] or [Ru(R)Cl(CO)(BTD)(PPh3)(2)] (BTD = 2,1,3-benzothiadiazole) by reaction with the nitrogen-sulfur mixed-donor ligand, 1-methyl-2-mercaptoimidazole (HMI), in the presence of base. In the same manner, [Os(CH=CHPh)(kappa(2) -MI)(CO)(PPh3)(2)] was prepared from [Os(CH=CHPh)(CO)CI(BTD)(PPh3)(2)]. The in situ hydroruthenation of 1-ethynyleyelohexan-1-ol by [RuH(CO)Cl(BTD)(PPh3)(2)] and subsequent addition of the HMI ligand and excess sodium methoxide yielded the dehydrated 1,3-dienyl complex [Ru(CH=CHC6H9)(kappa(2)-Ml)(CO)(PPh3)(2)]. Dehydration of the complex [Ru(CH=CH-CPh2OH)(kappa(2)-MI)(CO)(PPh3)(2)] with HBF4 yielded the vinyl carbene [Ru(=CHCH=CPh2)(kappa(2) -MI)(CO)(PPh3)(2)]BF4. The hydride complexes [MH(kappa(2)-MI)(CO)(PPh3)(2)] (M = Ru, Os) were obtained from the reaction of HMI and KOH with [RuHCl(CO)(PPh3)(3)] and [OsHCl(CO)(BTD)(PPh3)(2)], respectively. Reaction of [Ru(CH=CHC6H4CH3-4)(kappa(2)-MI)(CO)(PPh3)(2)] with excess HC=CPh leads to isolation of the acetylide complex [Ru(C=CPh)(kappa(2)-MI)(CO)(PPh3)(2)], which is also accessible by direct reaction of [Ru(C=CPh)Cl(CO)(BTD)(PPh3)(2)] with 1-methyl-2-mercaptoimidazole and NaOMe. The thiocarbonyl complex [Ru(CPh=CHPh)Cl(CS)(PPh3)(2)] reacted with HMI and NaOMe without migration to yield [Ru(CPh=CHPh)(kappa(2)-MI)(CS)(PPh3)(2)], while treatment of [Ru(CH=CHPh)Cl(CO)(2)(PPh3)(2)] with HMI yielded the monodentate acyl product [Ru{eta(1)-C(=O)CH=CHPh}(kappa(2)-MI)(CO)(PPh3)(2)]. The single-crystal X-ray structures of five complexes bearing vinyl, aryl, acetylide and dienyl functionality are reported.