Synthesis and structural characterization of Ni(II) complexes containing a heterocyclic NO donor ligand

Abstract

Five novel nickel(II) complexes have been successfully synthesized with a heterocyclic ligand, Opdac, [Ni(Opdac) 2]Cl 2 ( 1), [Ni(Opdac) 2(CH 3OH) 2]Br 2(CH 3OH) 2 ( 2), [Ni(Opdac) 2]I 2 ( 3), [Ni(Opdac) 2NO 3]NO 3 ( 4) and [Ni(Opdac) 2ClO 4]ClO 4 ( 5) where Opdac = 4-(1-H-1,3-benzimidazole-2-yl)-1,5-dimethyl-2-phenyl-1-2-dihydro-3-H-pyrazol-3-one. All the complexes were characterized by elemental analysis, molar conductivity, CHN analysis, magnetic susceptibility measurements, spectroscopic studies and TG/DTA methods. In all the complexes, Opdac acts as a bidentate ligand coordinating to Ni(II) ion via the benzimidazole imine nitrogen and the pyrazolone oxygen atoms. The complexes 1 and 3 have a tetrahedral geometry while 2, 4 and 5 have an octahedral geometry around the Ni(II) center.