CLUSTER SYNTHESIS .45. SYNTHESES AND STRUCTURAL CHARACTERIZATIONS OF GOLD PHOSPHINE DERIVATIVES OF THE LAYER-SEGREGATED CLUSTER PT(3)RU(6)(CO)(21)(MU(3)-H)(MU-H)(3)

Treatment of the compound Pt3Ru6(CO)(21)(mu(3)-H)(mu-H)(3) (1) with [Bu(4)N]OH followed by [Au-(PEt(3))][PF6] yielded two new layer-segregated platinum-ruthenium cluster complexes, Pt-3-Ru-6[Au(PET(3))](CO)(21)(mu-H)(3) (2; 22% yield) and Pt3Ru6Au(PEt(3))](2)(CO)(21)(mu 3-H)(2) (3; 5% yield), by the replacement of one and two of the hydride ligands in 1 with Au(PEt(3)) groupings, respectively. The yield of 3 can be increased to 18% by using larger amounts of [Bu(4)N]OH and [Au(PEt(3))][PF6]. Both compounds were characterized by IR, H-1 NMR, and single-crystal X-ray diffraction analyses. Compound 2 was formed from 1 by the substitution of the triply bridging hydride ligand with an Au(PEt(3)) grouping as a triple bridge on one of the Ru-3 triangles. The structure of the cluster of 3 is similar to that of 2, but the Au(PEt(3)) groups have assumed triply bridging positions across Ru2Pt triangles on opposite sides of the cluster and the two hydride ligands have adopted triply bridging sites on the two Ru-3 triangles. Crystal data: for 2, space group P2(1)/a, a = 17.520(2) Angstrom, b = 11.867(2) Angstrom, c = 20.987(4) Angstrom, beta = 92.46(1)degrees, Z = 4, 3348 reflections, R = 0.041; for 3, space group P2(1)/c, a= 17.351(4) Angstrom, c = 25.543(6) Angstrom, beta = 90.89(2)degrees, Z = 4, 3527 reflections, R = 0.051.