High yield synthesis of Ru-Pt mixed-metal cluster compounds

The reaction of [PPN](2)[Ru5C(CO)(14)] 1 or [PPN](2) [Ru6C(CO)(16)] 2 [PPN+ = (PPh3)(2) N+] with Pt(II) compounds of general formula [PtX2Cl2] [X-2 = (COD), (PPh3)(2) and (PPh3)( CO)] (COD = 1,5-cyclooctadiene) have been investigated and the products of simple or double addition, viz. [Ru5PtC( CO)(14) (COD)] 3, [Ru5PtC(CO)(14) (PPh3)(2)] 4, [Ru5PtC(CO)(15) (PPh3)] 5, [Ru5Pt2C(CO)(15) (PPh3)(2)] 6, [Ru6PtC(CO)(16) (COD)] 7, [Ru6Pt2C(CO)(15) (COD)(2)] 8, obtained. The molecular and crystal structures of 3-8 have been established by single crystal X-ray analysis. Compounds 3-7 all contain an intact Ru core with Pt fragment(s) capping triangular or square faces. The resulting mixed-metal core is octahedral for the clusters Ru5Pt and face-capped octahedral for the clusters RunPtm (n = 5 or 6; m = 2 or 1). Only compound 8 did not follow this pattern, with the Pt fragments bridging two Ru-Ru edges of the otherwise unaltered Ru6C core.