Cooperative formation of trinuclear zinc(II) complexes via complexation of a tetradentate oxime chelate ligand, salamo, and zinc(II) acetate.

Novel trinuclear zinc(II) complexes [Zn(3)L(2)(OAc)(2)] (L = salamo, 3-MeOsalamo) were synthesized, and their structures were determined by X-ray crystallography. Ligation of methoxy groups in the salamo ligand causes a significantly different coordination mode of the central zinc atom in the trinuclear system. The complexes between the salamo ligands and zinc(II) in methanol formed exclusively and very cooperatively. In contrast to other imine ligands, the mononuclear [ZnL] and other complexes are not observed at all.