HYDRIDE-BRIDGED DIPALLADIUM COMPLEXES CONTAINING DIPHOSPHINE LIGANDS

A series of hydride-bridged dipalladium complexes supported by bis(dip henylphosphino)methane(dppm) ligands has been prepared. The complexes [Pd2R2(mu-H) (mu-dppm)(2)]PF6 (R = Me, Et, Bu, CH2SiMe3, Ph) were gene rated by reduction, using NaBH3CN, of the corresponding halide-bridged species. The products are thermally stable, yellow solids, and they h ave been characterized by H-1 and P-31(LH) NMR spectroscopy. The ethyl complex [Pd2Et2(mu-H) (mu-dppm)(2)]PF, has been characterized further by X-ray crystallography. It crystallizes in the monoclinic space gro up P2(1)/c with a = 10.6160 (1), b = 12.8637 (1), c = 25.3739 (3) Angs trom, beta = 97.479 (1)degrees and Z = 2. The cation adopts an A-frame structure, with a Pd-Pd distance of 2.9933 (7) Angstrom.