Some transition metal complexes of Nitrogen, Sulphur donor ligand derived from substituted 1,2,4-triazole and 2-Chloro-5-nitrobenzaldehyde: Synthesis, spectral characterization, thermal and antimicrobial studies

Abstract

 A triazole-based ligand (HL) and its Nickel(II) and Zinc(II) complexes were prepared and characterized through various spectroscopic methods (UV-vis, IR, ¹H-NMR, fluorescence), elemental analysis, thermal analysis, and magnetic measurements. The ligand, 4-(2-Chloro-5-nitrobenzylideneamino)-5-mercapto-3-n-propyl-1,2,4-triazole, was synthesized by refluxing 4-Amino-5-mercapto-3-n-propyl-1,2,4-triazole with 2-Chloro-5-nitrobenzaldehyde. Both the Nickel(II) and Zinc(II) complexes showed octahedral geometries around the metal centres. IR and thermogravimetric analysis confirmed the presence of coordinated water molecules in the 1:1 metal complexes. The ligand and complexes were tested against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa) to evaluate antibacterial activity, and against two yeasts (Candida albicans, Saccharomyces cerevisiae) for antifungal testing. The in vitro antimicrobial tests showed that the metal complexes were found more effective than the free ligand.