Reactivity of [Os3(CO)9(μ3-η1,κ1-C9H6N)(μ-H)] towards Ph3EH (E = Si, Ge, Sn): Synthesis and structure of triosmium clusters bearing a Ph3E ligand

Abstract

The reactions of quinoline-capped triosmium cluster [Os3(CO)9(μ3-η1,κ1-C9H6N)(μ-H)] (1) with Ph3EH (E = Si, Ge, Sn) have been investigated. Cluster 1 reacts with Ph3EH in refluxing benzene to afford [Os3(CO)9(EPh3)(μ-η1,κ1-C9H6N)(µ-H)2] (2a, E = Si; 2b, E = Ge; 2c, E = Sn) and [Os3(CO)8(EPh3)(μ3-η1,κ1-C9H6N)(µ-H)2] (3a, E = Si; 3b, E = Ge; 3c, E = Sn). Control experiments confirm that 2 is a precursor of 3. Cluster 2 is formed via oxidative-addition of E–H bond to 1 whose decarbonylation leads to the formation of 3. The molecular structures of all the new clusters (except 3c) have been determined by X-ray crystallography. Both 2 and 3 exist as a pair of isomers in solution, and their fluxionality in solution has been probed by VT NMR experiments.