Zinc complexes of a new N,N,O ligand

The tridentate ligand N,N(2-dimethylaminoethyl)-3,5-ditert.-butyl-salicylaldimine (LH) results from the corresponding salicylic aldehyde and N,N-dimethyl ethylenediamine. With zinc salts it forms the mononuclear halide complexes [LZnCl.CH3OH] (1) and [LZnI.CH3OH] (2) and the presumably polymeric acetate [LZnOCOCH3] (3). With diethyl zinc and diphenylphosphoric acid it yields the phosphate complex [LZn-OPO(OPh)(2).CH3OH] (4). The coordination of the complexes, which is between trigonal bipyramidal and square pyramidal, and the character of the five donors in the phosphate complex represent the transition state of a hydrolytic substrate cleavage in a zinc enzyme.