Synthesis and Physico‐Chemical Studies of Some Mixed‐Ligand Complexes of bis(Benzoylacetonato)copper(II) with Some Biologically Active Heterocyclic Chelating Donors

Abstract

Six new mixed‐ligand complexes of copper(II) of the compositions [Cu(bzac)₂(L)₂], where bzacH = benzoylacetone and L = 3‐methyl‐2‐pyrazoline‐5‐one (MP) (1), 2,3‐dimethyl‐1‐phenyl‐3‐pyrazoline‐5‐one (DMPHP) (3), benzimidazole (BZL) (4) or benzothiazole(BZT) (5) and [Cu(bzac)₂(L–L)], where L–L = 4‐amino‐2,3‐dimethyl‐1‐phenyl‐3‐pyrazoline‐5‐one (ADMPHP) (2) or 2‐aminobenzothiazole (ABZT) (6), have been synthesized by the interaction of bis(benzoylacetonato)copper(II) with the ligands L and L–L. The compounds so obtained were characterized by analytical data, molar conductances, magnetic measurements, ESR, IR, and electronic spectral studies. Monomeric structures are suggested for these compounds.

Keywords:

• Keto‐enol tautomerism
• Mixed‐ligand β‐diketone complexes
• Heterocyclic chelating donors
• cis‐Octahedral

Acknowledgments

We are thankful to Professor S. D. Tripathi, Vice‐chancellor of this University, for encouragement, and Professor K. K. Mishra, Head, Department of Chemistry, for laboratory facilities and helpful discussion. Analytical facilities provided by the Central Drug Research Institute, Lucknow, India, and the Regional Sophisticated Instrumentation Centre, Indian Institute of Technology, Chennai, India, are gratefully acknowledged. Thanks are also due to Referee I for constructive suggestions regarding structures of the complexes.