INVESTIGATIONS ON ORGANOZINC COMPOUNDS .X. COORDINATION CHEMISTRY OF ORGANOZINC COMPOUNDS RZNZ - ORGANOZINC-OXYGEN DERIVATIVES OF POTENTIALLY BIDENTATE LIGANDS

The coordination chemistry of organozinc compounds RZnOD in which OD is a bidentate ligand such as 2-methoxyethoxide (I), 2-(dimethylamino)ethoxide (II), 8-hydroxyquinolinate (III, IV), N-phenylsalicylaldiminate (V, VI) and acetylacetonate (VII, VIII) has been studied. With the exception of tetrameric (I) which has a cubic structure, RZnOD compounds exist as dimers (V-VIII) or trimers (II-IV) in benzene solution as a result of intermolecular ZnO and intramolecular ZnD bridging. Valency angle strain largely determines the degree of association, the RZnOD derivatives being dimeric if a six-membered and trimeric if a five-membered chelate ring is present. This is supported by the results of a study of EtZnOCH2CH2CH2NMe2 which is benzene exists as a mixture of dimeric and tetrameric species. The complex-forming behaviour of RZnOD derivatives in the presence of mono- and bidentate ligands offers valuable information on the nature of these compounds. Complexes have been characterized in which N,N,N′,N′-tetramethylethylenediamine is thought to act as a bridging ligand. © 1968.