SYNTHESIS OF THE MIXED-METAL CLUSTERS [RU5RHC(CO)14(COD)Y] [Y=H, AU(PET3) OR AU(PPH3) - COD=CYCLOOCTA-1,5-DIENE] - REACTIONS OF [RU5RHC(CO)14(COD)(AU(PR3))] (R=PH OR ET) AND CRYSTAL-STRUCTURE OF [RU5RHC(CO)14(COD)(MU-3-AU(PPH3))]

Treatment of the pentaruthenium salt [N(PPh3)2]2[Ru5C(CO)14] with an e xcess of [Rh(cod)2][SbF6] (cod = cycloocta- 1,5-diene) yielded the mon oanion [Ru5RhC(CO)14 (cod)]- which has been isolated as its [N(PPh3)2] + salt 1. Reaction of the monoanion with HBF4.Et2O gave the hydrido de rivative [Ru5RhH(C) (CO)14 (cod)2] 2. Compound 1 reacted with the gold salts [Au(PPh3)]Cl and [Au(PEt3)]Cl, respectively, to yield the clust er compounds [Ru5RhC(CO)14 (cod) {Au(PPh3)}] 3 and [Ru5RhC-(CO)14(cod) {Au(PEt3)}] 4. Compound 3 crystallises in the triclinic space group P 1BAR (no. 2) with a = 15.993(3), b = 9.728(2), c = 13.900(3) angstrom, alpha = 90.29(2), beta = 99.97(2), gamma = 88.36(2)-degrees. The meta l core geometry consists of a central Ru5Rh octahedron with one Ru3 fa ce capped by a mu3-Au(PPh3) fragment [Ru-Ru 2.787(1)-3.093(1); Ru-Rh 2 .892(1)-2.952(1); Ru-Au 2.735(1)-3.082(1) angstrom]. The reactions of 3 and 4 with norbornadiene, PPh3 and P(OMe)3 are reported.