The complexes trans-[Ru(PMe3)4(C = CPh)2] and trans-[Ru(PMe3)4(C = CC6H4C6H4C = CSnMe3)2] have been prepared from the reaction between trans-[Ru(PMe3)4Cl2] and an excess of either Me3SnC = CPh or Me3SnC = CRC = CSnMe3 (R = p-C6H4C6H4), respectively. However, if only one equivalent of the latter reagent is used the rod-like polymeric species trans-[-Ru(PMe3)4C = CRC = C-]n can be isolated.