95387-55-6Relevant articles and documents
Preparation and characterization of heterobimetallic halogen-bridged palladium-platinum complexes. Crystal and molecular structure of [(PEt3)CIPd(μ-Cl)2PtCl(PEt3)]
Clark, Howard C.,Ferguson, George,Jain, Vimal K.,Parvez, Masood
, p. 1477 - 1482 (2008/10/08)
Attempts to prepare and characterize unambiguously heterobimetallic complexes of the type [(PR3)ClPd(μ-Cl)2PtCl(PR3)](R = Et, n-Pr, Bu, Ph; PR3 = PMe2Ph) using infrared, 31P and 195Pt NMR, and mass spectroscopies are described. It is established that, in solution, an equilibrium exists between [(PR3)ClPd(μ-Cl)2PtCl(PR3)], [(PR3)2Pd2Cl4], and [(PR3)2Pt2Cl4], the latter two species always being in 1:1 molar ratio; this equilibrium is temperature independent but is influenced by excess of either one of the dimers [(PR3)2M2Cl4] (M = Pt, Pd). The reactions of the heterobimetallic products with SnCl2·2H2O have been investigated, as well as the bridge-cleavage reactions with various donor ligands, in order to elucidate the chemical behavior of the heterobimetallic dichloro bridge; neutral ligands appear to be distributed equally between Pd and Pt. Crystals of the reaction product, with a composition corresponding to [(PEt3)ClPd(μ-Cl)2PtCl(PEt3)] are monoclinic, space group P21/n, with a = 7.590 (2) A?, b = 12.216 (1) A?, c = 12.119 (1) A?, and β = 101.87 (1)° With Z = 2 the molecules must lie about inversion centers, and the Pd and Pt atoms are mutually disordered. The structure was solved by the heavy-atom method and refined by full-matrix least-squares calculations with anisotropic thermal parameters; R = 0.030 and Rw = 0.033 for 2451 observed reflections. The unique metal atom has slightly distorted square planar geometry with M-P = 2.214 (1), M-Cl (terminal) = 2.275 (1), M-Cl (bridging trans to P) = 2.437 (1), and M-Cl (bridging trans to Cl) = 2.314 (1) A?. The data do not unambiguously identify the solid product but, in combination with the NMR and mass spectroscopic data, do establish conclusively the existence of these beterobimetallic complexes.