Notes. Preparation of two mixed-metal carbonyl clusters based on the platinumtriosmium core. X-Ray crystal structure of [Os3PtH2(cod)(CH2)(CO)9](cod = cyclo-octa-1,5-diene)

Abstract

Two saturated platinumtriosmium clusters, [Os₂PtH₂(cod)(CH₂)(CO)₉](1) and [Os₃PtH₂(CH₂)(CO)₁₁](2), have been prepared in 10–20% yield, by refluxing [Os₃H₂(CO)₁₀] and [PtMe₂(cod)](cod = cyclo-octa-1,5-diene) in toluene. The crystal structure was solved for (1); it comprises a saturated tetrahedral Os₃Pt core bridged by two hydrides and a methylene group. The platinum atom is η⁴-co-ordinated by the cod ligand. The other cluster, (2), has the cod ligand substituted by two carbonyls but is expected to be similar to (1) in all other respects. The bridging methylene group probably originates from the starting methylplatinum complex. The co-ordinated cod ligand of (1) has been substituted quantitatively, by treatment with carbon monoxide, to give (2).