Synthesis, characterization and antimicrobial activity of transition metal complexes of 4-[(2-hydroxy-4-methoxyphenyl)methyleneamino]-2,4-dihydro-3H-1,2,4-triazole-3-thione

A novel nitrogen containing 4-[(2-hydroxy-4-methoxyphenyl)methyleneamino]-2,4-dihydro-3H-1,2,4-triazole-3-thione ligand (H2L) was synthesized by using an equimolar ratio of 4-amino-1,2,4-triazole-3-thione and 2-hydroxy-4-methoxybenzaldehyde. A series of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes was synthesized by using the ligand. The synthesized ligand and transition metal complexes were characterized by IR, 1H NMR, 13C NMR, Mass spectrometry, UV, XRD and TGA investigation methods. Spectral data suggests that the ligand acts as a tridentate SNO donor. Further, the synthesized H2L ligand and their metal complexes were screened for antimicrobial activity. The results of biological activities showed that the metal complexes have higher antifungal as well as antibacterial activity as compared to the parent H2L ligand against the tested microbes.