Platinum‐Osmium Heterometallic Clusters Containing N‐Heterocyclic Carbene Ligands and an Electron‐Deficient Tetraosmium By‐Product

The room temperature reaction of [Os 3 (CO) 12 ] ( 1 ) with three molar equivalents of [PtCl(allyl)(NHC)] ( 2 ) in the presence of KO t Bu afforded the heterometallic clusters [PtOs 3 (CO) 12 (NHC)] ( 3 ), [Pt 2 Os 3 (CO) 12 (NHC) 2 ] ( 4 ), and [Pt 3 Os 3 (CO) 12 (NHC) 3 ] ( 5 ), together with a trace amount of the tetraosmium cluster [Os 4 (CO) 10 (µ‐H) 2 (NHC)] ( 6 ). The reaction pathway is thus similar to that for Pd analogues, with the exception of cluster 6 . Unlike their Pd analogues, however, these clusters do not appear to readily interconvert. With a valence electron count of 58, clusters 6 are deficient by four electrons.