Synthesis and characterization of some mixed-ligand picrate complexes of nickel(II) involving heterocyclic nitrogen donors

The present communication describes the synthesis of some mixed-ligand hexacoordinated picrato complexes of nickel(II) of the composition [Ni(PA)(2)(L-L)(2)], where PAH=picric acid and L-L=2-aminobenzothiazole (ABZT), 2-(2'-aminophenyl)benzothiazole (2'-AMPHBZT), 2-(3'-aminophenyl)benzothiazole (3'-AMPHBZT), bipyridine (bpy), o-phenanthroline (phen) or 2,6-bis(benzimidazyl)pyridine (BBZLPY). These complexes were obtained by the interaction of nickel(II) picrate with the corresponding ligands L-L in methanol. The resulting compounds have been characterized by elemental analyses, magnetic, molar conductance and decomposition temperature measurements, electron spin resonance, infrared and electronic spectral studies. All the complexes are thermally stable and behave as non-electrolytes. An octahedral structure has been tentatively proposed for these complexes.