Synthesis, characterization and antimicrobial studies of Cu (II) and Zn (II) complexes of Schiff base derived from 2-Amino-2-hydroxybenzoic acid and 2-hyroxybenzaldehyde

Abstract

Schiff base derived from condensation reaction of 4-amino-2-hydroxybenzoic acid and 2-hydroxybenzaldehyde was synthesized. The aim of this work is to synthesize, characterize and study the antimicrobial activities of Schiff base and their Cu (II) Zn (II) complexes. It was refluxed with metals (II) chlorides which results in the formation of the corresponding metal (II) complexes in good yield. The compounds were characterized on the basis of their melting point, decomposition temperature, Fourier transform infrared spectroscopy, magnetic susceptibility, conductivity measurement and determination of metal - ligand ratio. The IR spectral data revealed azomethine peak of the Schiff base at while for the complexes, the peak was found within. The molar conductance of the Cu (II) and Zn(II) complexes were found to be 24.8 and 6.2 Ω^-1cm² Mol^-1 respectively which indicated that, the complexes were non- electrolytes. The decomposition temperature of Cu (II) and Zn (II) complexes were found to be 292 ^oC and 255 ^oC respectively, showed that the complexes are stable. Cu (II) complexes exhibit Magnetic moment values of 1.72 which suggested that the complexes, is paramagnetic while Zn (II) to be diamagnetic. Determination of metal: ligand ratio was 1:2. The biological screening of the compound were studied against three bacterial and two fungal isolates; S. aureus, E. coli and P. aeruginosa, M. indicus and A. flavus. Septrin and Nystatin were used as control for the bacteria and fungi respectively. The result revealed that the complexes exhibit higher activities than the Schiff base but lower than the control.