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 = anion of the 2-hydroxyacetophenone Schiff base of S-methyl-dithiocarbazate)

Summary 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-hydroxyacetophenone and S-alkyl esters of dithiocarbazic acid; M = Ni^II or Cu^II; R = Me or CH₂Ph; B = py, phen or dipy have been synthesized and characterized by a variety of physicochemical techniques. Magnetic and spectroscopic data support an oxygen-bridged binuclear structure for the M(Ap-SR)] complexes. The M(Ap-SR)py] complexes are four-coordinate 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 has been determined by X-ray crystallography. It has an approximately square-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 around the Ni^II ion is occupied by the N of the pyridine ligand.