Complexes with platinum-ruthenium bonds: Synthesis, structure, and fluxionality of Pt3Ru cluster complexes

The reaction of [Pt-3(mu(3)-CO)(mu-dppm)(3)] [PF6](2), 1, dppm Ph2PCH2PPh2, with [HRu(CO)(4)](-) initially gives [Pt-3(mu-H)(mu-dppm)(3){Ru(CO)(4)}](), 2, which contains a PtRu(mu-H) unit. In solution, complex 2 rearranges t o the cluster [Pt3Ru(mu-H)(CO)(2)(mu-CO)(2)(mu-dppm)3](+), 3, which has bee n characterized by X-ray structure determination to have a butterfly struct ure with Euthenium at a wingtip position and which contains a Pt-2(mu-H) un it. Both complexes 2 and 3 exhibit fluxionality, which is defined by low-te mperature NMR studies.