Synthesis, characterization and X-ray crystal structures of thiolate sulfur-bridged dimeric copper(II) complexes of the 2-aminoacetophenone Schiff base of S-methyldithiocarbazate

Abstract

Copper(II) complexes of general empirical formula, Cu(apsme)X (apsme=monodeprotonated form of the 2-aminoacetophenone Schiff base of S-methyldithiocarbazate (Hapsme); X=Cl−, Br−, NCS−) have been prepared and characterised by a variety of physico-chemical techniques. The crystal and molecular structures of the Schiff base, Hapsme (1), [Cu(apsme)Br] (2), [Cu(apsme)(NCS)] (3) and [Cu(apsme)Cl] (4) have been determined by X-ray diffraction. In the solid state the copper(II) complexes 2, 3 and 4 are dimers in which the anionic Schiff base, (apsme−) coordinates with a copper(II) ion as a tridentate NNS chelating agent via the amino nitrogen atom, the azomethine nitrogen atom and the thiolate sulfur atom. The fourth and fifth coordination positions of a copper atom are occupied by a co-ligand and bridging thiolate sulfur atoms, respectively.