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

The complexes, [Cu(NNS)CH3COO] and [Cu(NNS)(2)] (HNNS = the 6-methylpyridin e-2-carboxaldehyde Schiff base of S-methyldithiocarbazate) have been synthe sized and characterized by a variety of physico-chemical techniques. The cr ystal structures of these complexes have also been determined by X-ray diff raction studies. The mono-ligated acetato complex has a square-planar struc ture with the copper(II) ion lying in an approximate plane of four coordina ting atoms, three of which are supplied by the Schiff base and the fourth i s provided by an oxygen of the anion. The bis-ligand copper(II) complex, [C u(NNS)(2)] has a distorted octahedral structure in which the Schiff bases a re bound to the copper(II) ion as NNS tridentate ligands coordinating via t he pyridine nitrogen atom, the azomethine nitrogen atom and the thiolato su lfur atom. The ligands are arranged meridionally around the copper(II) ion. Infrared and electronic spectral data for both complexes are consistent wi th their structures. (C) 1999 Elsevier Science S.A. All rights reserved.