Synthetic, spectroscopic and X-ray crystallographic structural studies on some copper(II) complexes of the 6-methylpyridine-2-carboxaldehyde Schiff base of S-methyldithiocarbazate

Abstract

The complexes, [Cu(NNS)CH 3COO] and [Cu(NNS) 2] (HNNS=the 6-methylpyridine-2-carboxaldehyde Schiff base of S-methyldithiocarbazate) have been synthesized and characterized by a variety of physico–chemical techniques. The crystal structures of these complexes have also been determined by X-ray diffraction studies. The mono-ligated acetato complex has a square-planar structure with the copper(II) ion lying in an approximate plane of four coordinating atoms, three of which are supplied by the Schiff base and the fourth is provided by an oxygen of the anion. The bis-ligand copper(II) complex, [Cu(NNS) 2] has a distorted octahedral structure in which the Schiff bases are bound to the copper(II) ion as NNS tridentate ligands coordinating via the pyridine nitrogen atom, the azomethine nitrogen atom and the thiolato sulfur atom. The ligands are arranged meridionally around the copper(II) ion. Infrared and electronic spectral data for both complexes are consistent with their structures.