The reactions of [RuHCl(CS)(PPh3)3] with R1CCR2 (R1 = R2 = H, Ph, CO2Me; R1 = H, R2 = C6H4Me-4; R1 = CCPh, R2 = Ph) lead to the five- or six-coordinate (R1 = R2 = CO2Me) σ-alkenyl complexes [Ru(CR1CHR2)Cl(CS)(PPh3)2], the stilbenyl derivative being also formed by thermolysis of [RuCl(κ2-O2CH)(CS)(PPh3)2] in the presence of diphenylacetylene. These complexes rapidly react with carbon monoxide to provide the bidentate thioacyl complexes [Ru(η2-SCCR1CHR2)Cl(CO)(PPh3)2] (R1 = R2 = H, Ph; R1 = H, R2 = Ph; R1 = CCPh, R2 = Ph) or the σ-alkenyl tautomer [Ru(CR1CHR2)Cl(CO)(CS)(PPh3)2] (R1 = R2 = CO2Me), depending on the alkenyl substituent. The compound [RuHCl(CS)(PPh3)3] reacts with 1/2 equiv of 1,4-diethynylbenzene to provide the coordinatively unsaturated bimetallic species [(Ph3P)2(SC)ClRu(CHCHC6H4CHCH)RuCl(CS)(PPh3)2] in situ, which undergoes migratory insertion on addition of carbon monoxide to give the bis(thioacyl) species [(Ph3P)2(OC)ClRu(η2-SCCHCHC6H4CHCHCS-η2)RuCl(CO)(PPh3)2]. On reaction with BSD (2,1,3-benzoselenadiazole), [Ru(CHCH2)Cl(CS)(PPh3)2] gives [Ru(CHCH2)Cl(CS)(BSD)(PPh3)2] without migration of the alkenyl group. The complex [RuHCl(CS)(BSD)(PPh3)2] results from the reaction of [RuHCl(CS)(PPh3)3] and BSD, and this complex hydroruthenates alkynes cleanly to provide [Ru(CR1CHR2)Cl(CS)(BSD)(PPh3)2], carbonylation of which leads to loss of BSD and formation of [Ru(η2-SCCR1CHR2)Cl(CO)(PPh3)2]. Addition of carboxylate donors R‘CO2- (R‘ = H, Fc) to the complexes [RuRCl(CS)(PPh3)2] (R = CHCH2, C(CCPh)CHPh) results in the complexes [RuR(κ2-O2CR‘)(CS)(PPh3)2], without migratory insertion. A trimetallic example, Fe[C5H4CO2Ru{C(CCPh)CHPh}(CS)(PPh3)2]2, was formed in the corresponding reaction with 1,1‘-ferrocenedicarboxylic acid and Et3N. The crystal structures of the complexes [Ru(CPhCHPh)Cl(CS)(PPh3)2], [Ru{C(CCPh)CHPh}Cl(CS)(PPh3)2], [Ru{η2-SCC-(CCPh)CHPh}Cl(CO)(PPh3)2], [Ru{C(CCPh)CHPh}(κ2-O2CFc)(CS)(PPh3)2] and Fe[C5H4CO2Ru{C(CCPh)CHPh}(CS)(PPh3)2]2 are reported.