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

Abstract

Copper(II) complexes of the Schiff base 2,3‐dimethyl‐4‐formyl‐(benzhydrazide)‐1‐phenyl‐3‐pyrazolin‐5‐one (L) of the general formula [Cu(L)₂]X₂ (X = ClO₄ or NO₃), [Cu(L)Cl₂] and [Cu(L)₂Br₂] have been synthesized and characterized by elemental analyses, electrical conductance in non‐aqueous solvents, infrared, electronic and EPR spectra, as well as magnetic susceptibility measurements. In these complexes, the ligand acts as a neutral bidentate unit coordinating through the azomethine nitrogen atom and the carbonyl oxygen of the pyrazolone ring. In the perchlorate and nitrate complexes both anions remain ionic, while in the corresponding halide complexes both anions are coordinated to the metal ion. The perchlorate, nitrate and chloride complexes are of square‐planar geometry while the bromide complex is of distorted octahedral geometry.

Acknowledgments

We thank the Heads of the Regional Sophisticated Instrumentation Centers at the Indian Institute of Technology, Chennai, and the Indian Institute of Technology, Mumbai, for some instrumental analyses. We also thank the Mahatma Gandhi University, Kottayam, for providing laboratory facilities and the University Grants Commission for awarding a Teacher Fellowship to one of us (KCR) under the faculty improvement program. Also, we wish to express our heartfelt thanks to Dr. Siby Joseph and Dr. N.T. Madhu for some fruitful discussions.