SYNTHESIS, CHARACTERISATION AND ANTIMICROBIAL ACTIVITIES OF MIXED LIGAND NICKEL(II),COPPER(II) AND ZINC(II) COMPLEXES OF BENZALDEHYDE WITH 1,10-PHENANTHROLINE, 2,2′-BIPYRIDINE AND ETHYLENEDIAMINE

Abstract

Nickel(II), copper(II) and zinc(II) mixed ligand complexes of benzaldehyde with 1,10-phenanthroline, 2,2′-bipyridine  and ethylenediamine have been synthesised and characterised by metal analysis, infrared spectroscopy, electronic spectra studies, magnetic susceptibility measurement and antimicrobial activities. The infrared spectra of the complexes confirmed the coordination through the carbonyl oxygen of the benzaldehyde while the electronic transitions are consistent with the adoption of octahedral geometry for all the synthesised complexes. The magnetic moment of the synthesised complexes suggested that all the complexes were paramagnetic except Zn(II) complex which was diamagnetic. The microbial susceptibility testing showed that the copper complexes had stronger antibacterial and antifungal activity than nickel and zinc complexes. Notably, [Cu(Bz)₂Bipy(NO₃)₂] and [Ni(Bz)₂(phen)Cl₂].H₂O showed no antifungal activity.