Synthesis and structure of nickel(I) and platinum(I) hydride dimers having identical ancillary ligands

The preparation and structures of two new dinuclear hydrides are reported. Reaction of KBEt3H with the nickel(II) precursor Ni(dippp)Cl-2 (dippp = 1,3 bis (diisopropylphosphino) propane) leads to the formation of the dinuclear complex [(dippp)Ni](2)(mu-H)(2). The single crystal X-ray structure of this Ni(I) dimer shows that the hydrides are symmetrically bridging with the two Ni(dippp) planes staggered with respect to each other by an angle of 75 degrees. The corresponding reaction of KBEt3H with the platinum(II) precursor Pt(dippp)I, leads to the formation of the dinuclear complex [(dippp)PtH](2). The single crystal X-ray structure of this Pt(I) dimer shows that the hydrides are terminal with the corresponding Pt(dippp) planes orthogonal (92.3 degrees) to each other. The structures of these two Group 10 hydride dimers are compared to the known Pd(I) dimer [(dippp)Pd](2)(mu-H)(2). Crystal data: [(dippp)Ni](2)(mu-H)(2) (1) (C30H70Ni2P4), monoclinic, a = 11.513(2), b = 16.420(3), c = 19.696(4) Angstrom, beta = 92.40(2)degrees, Z = 4, space group C2/c', [(dippp)PtH](2) (5) (C30H70P4Pt2), triclinic, a = 11.529(1), b = 16.581(1), c = 11.018(2) Angstrom, alpha = 91.11(1), beta = 107.10(1), gamma = 106.166(8)degrees, Z = 2, space group P1. The structures were solved by Patterson and direct methods and were refined by full-matrix least-squares procedures to R = 0.0503 and 0.042 (R-w = 0.0565 and 0.038) for 2487 and 6189 reflections, respectively. (C) 1997 Elsevier Science S.A.