Synthesis, magnetic, and spectral studies of some mixed-ligand complexes of copper(II) involving diphenic acid and pyridine or aniline derivatives

New mixed-ligand hexa-coordinated diphenato complexes of copper(II) having the general formula [Cu(DPA)(L)(2)], where DPAH(2) = diphenic acid and L = nicotinamide (NICA), 2-cyanopyridine (2-CPY), 3-cyanopyridine (3-CPY) and 4-cyanopyridine (4-CPY) or aniline derivatives, such as, o-toluidine (o-TD), in-toluidine (m-TD) or o-phenetidine (o-PD), have been prepared by the interaction of an aqueous solution of cupric chloride and ethanolic solutions of diphenic acid and the corresponding ligand L, in the mole ratio of 1:1:2. The resulting products have been characterized on the basis of analytical data, molar conductances, magnetic measurements, infrared, electronic and electron spin resonance spectral studies. All of the complexes are thermally stable and behave as non-electrolytes. A square-planar geometry has been suggested for these complexes.