The synthesis of heteronuclear clusters containing cyclopentadienyl- or pentamethylcyclopentadienyliridium and ruthenium or osmium

The reaction of Cp*Ir(CO)2 or CpIr(CO)2 with Ru3(CO)12 under a hydrogen atmosphere afforded the heterometallic clusters Cp*IrRu3(μ-H)2(CO)10 and CpIrRu3(μ-H)2(CO)10, respectively, in moderate yields. In the former reaction, the tetrahydrido cluster Cp*IrRu3(μ-H)4(CO)9 was also formed in trace amounts, although this cluster can be obtained in high yields by the hydrogenation of Cp*IrRu3(μ-H)2(CO)10; the Cp analogue was not obtainable. The reaction of Os3(μ-H)2(CO)10 with Cp*Ir(CO)2 afforded the osmium analogue Cp*IrOs3(μ-H)2(CO)10 in 70% yield, along with a trace amount of the pentanuclear cluster Cp*IrOs4(μ-H)2(CO)13. Hydrogenation of Cp*IrOs3(μ-H)2(CO)10 afforded Cp*IrOs3(μ-H)4(CO)9 in excellent yield. The reaction of Cp*Ir(CO)2 with Os3(CO)10(CH3CN)2 afforded the known trinuclear cluster Cp*IrOs2(CO)9 and the novel cluster Cp*IrOs3(CO)11. Solution-state NMR studies show that the hydrides in the iridium–ruthenium clusters are highly fluxional even at low temperatures while those in the iridium–osmium clusters are less so.

The reaction of Cp*Ir(CO)2 or CpIr(CO)2 with Ru3(CO)12, Os3(μ-H)2(CO)10 or Os3(CO)10(CH3CN)2 afforded tetrahedral heteronuclear clusters in good to moderate yields. Solution-state NMR studies show that the hydrides in the iridium–ruthenium clusters are highly fluxional even at low temperatures while those in the iridium–osmium clusters are less so.Figure optionsDownload as PowerPoint slide