Hydridostannylene Derivatives of Magnesium and Calcium

Reactions of a m-terphenylhydridostannylene with β-diketiminato magnesium and calcium hydrides provide bis-μ₂-hydrido species, the heterobimetallic constitutions of which are maintained after the addition of THF donor solvent. In both cases, reactions with hex-1-ene result in the formation of tetravalent organostannyl alkaline earth derivatives. Whereas the magnesium reagent undergoes facile twofold addition, the calcium-centered process is arrested after a single alkene reduction event. This contrasting behavior is assessed to result from the heavier alkaline earth element's ability to form a persistent polyhapto interaction with an arene substituent of the m-terphenyl ligand.