Preparation, characterization and X-ray structures of 1-methylisatin 3-thiosemicarbazone copper, nickel and cobalt complexes

Copper, nickel and cobalt complexes of 1-methylisatin 3-thiosemicarbazone (HL) have been synthesized and characterized by means of spectroscopic techniques. The X-ray crystal structures of [CuClL](n) (1), [NiL2] (2), [CoL2]2[CoCl4](.)2EtOH (3) were also determined. In all compounds the monodeprotonated ligand behaves as O, N, S terdentate. In the copper complex the coordination geometry is square-pyramidal with the ligand and a chlorine atom lying on the basal plane; a bridging sulphur atom in axial position forms polymeric chains. The nickel atom of complex 2 is surrounded by six donor atoms of two ligand moieties in a distorted octahedral fashion. The molecular structure of compound 3 consists of octahedral [CoL2](+) cations, [CoCl4](2-) anions and solvate ethanol molecules. (C) 2002 Elsevier Science Ltd. All rights reserved.