NICKEL(II) AND COPPER(II) COMPLEXES OF ONS LIGANDS FORMED FROM 2-HYDROXYACETOPHENONE AND S-ALKYLDITHIOCARBAZATES AND THE X-RAY CRYSTAL-STRUCTURE OF THE [NI(AP-SME)PY] COMPLEX (AP-SME EQUALS ANION OF THE 2-HYDROXYACETOPHENONE SCHIFF-BASE OF S-METHYLDITHIOCARBAZATE)

New nickel(II) and copper(II) complexes of general formulae [M(Ap-SR)] and [Ap-SR)B] (Ap-SR = dianionic forms of the Schiff bases of 2-hydro xyacetophenone and S-alkyl esters of dithiocarbazic acid; M = Ni-II or Cu-II; R = Me or CH(2)Ph; B = py, phen or dipy) have been synthesized and characterized by a variety of physicochemical techniques. Magneti c and spectroscopic data support an oxygen-bridged binuclear structure for the [M(Ap-SR)] complexes. The [M(Ap-SR)py] complexes are four-coo rdinate and square planar, whereas the [M(Ap-SR)B] complexes (B = phen or dipy) are five-coordinate and probably trigonal bipyramidal. The [ Cu(Ap-SR)B] complexes (B = py, phen or dipy) obey the Curie-Weiss law over the 298-93 K range. The structure of the [Ni(Ap-SMe)py] complex h as been determined by X-ray crystallography. It has an approximately s quare-planar structure in which the doubly-deprotonated Schiff base is coordinated to the Ni-II ion via the azomethine N atom, the phenolic O atom and the thiolato S atom. The fourth coordination position aroun d the Ni-II ion is occupied by the N of the pyridine ligand.