Synthesis, structural characterization and antimicrobial activity of nickel(II) tetrathiocyanato dicuperate(I) complexes with some acyl hydrazones

Abstract

Heterobimetallic complexes of the type Ni[Cu(SCN)₂]₂ · L (where L = acetophenone benzoylhydrazone, acetophenone isonicotinoyl hydrazone, acetophenone salicyloylhydrazone (ash), acetophenone anthraniloylhydrazone, p-hydroxy acetophenone benzoylhydrazone, p-hydroxy acetophenone isonicotinoyl hydrazone p-hydroxy acetophenone salicyloylhydrazone (phash), p-hydroxy acetophenone anthraniloyl hydrazone), were synthesized and characterized. The complexes are polymeric, insoluble in common organic solvents and are nonelectrolytes. Magnetic moments and electronic spectral studies suggest a spin-free octahedral geometry for the complexes. IR spectra show the bidentate nature of all the ligands bonding through >C=O and >C=N–groups. The SCN group acts as a bridge between two metal centers. X-ray powder diffraction parameters for Ni[Cu(SCN)₂]₂ · ash and Ni[Cu(SCN)₂]₂ · phash correspond to orthorhombic and tetrahedral crystal lattices, respectively, for these complexes. The complexes show a significant antifungal activity against Rizoctonia, Stemphylium and Aspergillus sp. and antibacterial activity against Clostridium and Pseudomonas sp. The metal complexes are more active than the ligands.

Keywords:

• nickel(II)
• copper(I)
• bimetallic
• antimicrobial
• structure
• hydrazones

Acknowledgments

The authors thank the Director, Institute of Engineering and Technology, C.S.J.M. University Kanpur for providing laboratory facilities; the Head, Chemistry Department, Indian Institute of Technology, Kanpur for recording IR spectra, electronic spectra and X-ray diffraction patterns; and Dr Nand Lal, Institute of Life Science, C.S.J.M. University Kanpur for his help in antimicrobial screening.