Dinuclear Zinc Hydride Supported by an Anionic Bis(N‐Heterocyclic Carbene) Ligand

Methylene‐linked bis( N , N ′‐di‐ tert ‐butylimidazol‐2‐ylidene) 1 reacted with diethylzinc to give dinuclear zinc ethyl compound 2 , which contains a formally anionic bis(carbene) ligand as a result of deprotonation of the methylene bridge. The reaction of 2 with PhSiH 3 gave the phenylsilyl compound 3 . The zinc hydride 4 was obtained by the reaction of 2 with LiAlH 4 or Ph 3 SiOH followed by treatment with PhSiH 3 . X‐ray diffraction studies show that compounds 2 , 3 , and 4 all have a similar dimeric structure with D 2 h symmetry. The reaction of hydride 4 with carbon dioxide and N , N ′‐diisopropylcarbodiimide gave formato ( 5 ) and formamidinato ( 7 ) derivatives as a result of the insertion of the heterocumulene into both ZnH bonds. Reaction with Ph 2 CO gave the diphenylmethoxy compound 6 . Hydride 4 shows catalytic activity in the hydrosilylation of 1,1‐diphenylethylene and methanolysis of silanes.