Structural Investigation of Homonuclear Pt_2 and Heteronuclear PdPt Complexes Containing a Metal-Metal Bond Bridged by Hydrido and Sulfido Ligands

摘要

The complex [Pt2(μ-H)(μ-S)(dppe)2](PF6) undergoes a displacive order-disorder transformation at ca 230 K. The low-temperature structure is ordered with one cation-anion pair as the asymmetric unit in space group P2xjn. At room temperature the b axis is halved and the space group is P2, imposing crystallographic twofold rotation symmetry on both ions; the anion shows major disorder and there is probably minor disorder in the cation, but its internal geometry remains essentially unchanged. The heteronuclear complex [PdPt(μ-H)(μ-S)(dppe)2](PF6) is isostructural with the Pt2 complex at room temperature. All three structures have been determined crystallographically and both complexes have been extensively characterized by NMR spectroscopy, unambiguously confirming the genuine heteronuclear nature of the mixed-metal complex and the presence of the bridging hydride ligand.