Complexes of Nickel(II) with 2,3‐Dimethyl‐4‐formyl(benzhydrazide)‐1‐phenyl‐3‐pyrazolin‐5‐one

Abstract Nickel(II) complexes of the Schiff base 2,3‐dimethyl‐4‐formyl‐(benzhydrazide)‐1‐phenyl‐3‐pyrazolin‐5‐one (L) with the formulae [Ni(L)2 (ClO4)]ClO4, [Ni(L)2(NO3)](NO3), and [Ni(L)2X2] (X = Cl, Br, or I) have been synthesized and characterized by elemental analyses, electrical conductance in nonaqueous solvents, infrared and electronic spectra as well as magnetic susceptibility measurements. In these complexes, L acts as a neutral bidentate ligand coordinating through the azomethine nitrogen and the carbonyl oxygen of the pyrazolone ring. In the perchlorate and nitrate complexes one of the anions is coordinated to the metal ion in a bidentate fashion while in the halide complexes both the anions are coordinated. An octahedral geometry is assigned around the nickel(II) ion in all these complexes.