Thermal behaviour and antimicrobial assay of some new zinc(II) 2-aminobenzoate complex compounds with bioactive ligands.

New zinc(II) 2-aminobenzoate complexes with general formula Zn(2-NHbenz)(L) (where 2-NHbenz is 2-aminobenzoate, and L is phenazone, N-methylnicotinamide, nicotinamide and isonicotinamide) were prepared and characterized by elemental analysis and by FTIR spectroscopy. The stability and thermal behaviour of the compounds were studied by thermal analysis techniques (TG/DTG, DTA), and the decomposition reactions were proposed. The decomposition of the studied compounds is always a multistep process, when after the release of the bioactive ligand, 2-aminobenzenecarbaldehyde, 2-aminobenzene and carbon dioxide were evolved. The solid intermediate compounds were confirmed by FTIR spectroscopy, and the volatile products were identified by mass spectrometry. The final solid product of thermal decompositions was zinc oxide, which was confirmed by XRD and FTIR analysis. The non-isothermal kinetic investigation of Zn(2-NH2benz)(mnad) decomposition in air was performed by means of isoconversional methods, for a better understanding of the undergoing processes. The antimicrobial assay was carried out comparatively for the investigated compounds; they have higher biological activity towards Staphylococcus aureus, Escherichia coli and Candida albicans in comparison with zinc(II) 4-bromobenzoates. [ABSTRACT FROM AUTHOR]