Microwave-Assisted Synthesis, Spectral, Thermal and Antimicrobial Studies of VO(IV) and Co(II) Metal Complexes Derived From 2-pyridine Carboxaldehyde

The incorporation of transition metal ions such as Co(II) and VO(IV) into the framework of azomethine-based ligands is of significant interest, as it modulates their structure, stability, and functional potential. These compounds are used as models for biological systems and find application in catalytic reactions; and used as pharmaceutical agents. In this report, we have synthesized some VO(IV) and Co(II) metal complexes with 2-pyridine carboxaldehyde and 4-amino benzoic acid (PAB) Schiff base ligand by microwave irradiation as well as reflux heating methods. Synthesized Schiff base and its metal complexes exhibit good biological activity against the bacteria; S. typhi, B. subtilis, E. coli and fungi F. oxysporum, A. niger, C. albicans. The antimicrobial data show that the metal complexes of VO(IV) and Co(II) are better antimicrobial agents as compared to the PAB Schiff base ligand. All the compounds used in the synthesis of Schiff base and metal complexes were analytical grade and purchased from HI media and CDH Chemie. The synthesized compounds were characterized by various physicochemical and spectral techniques including; elemental analyses; Fourier transform infrared spectroscopy; molar conductance; UV-Vis spectroscopy; magnetic susceptibility; and thermal analyses. All the compounds were coloured and stable in air and moisture. The analytical data revealed that all the complexes exhibited 1:2 (metal-to-ligand) ratio. Thermogravimetric data indicated the stability and degradation pattern of the complexes.