Green Synthesis, Spectral, Thermal Characterization and Biological Activity of Schiff base Ligand Derived from 3-amino-1,2,4-triazol and its Metal Complexes

Abstract

Green, efficient and clean synthesis of a Schiff base ligand, 1-(((1H-1,2,4-triazol-3-yl) imino) methyl) naphthalen-2-ol (TMN) has been synthesized in equimolar reaction (1:1) of 3-amino-1,2,4-triazole as a primary amine and 2-hydroxy-1-naphthaldehyde as an aldehyde using microwave irradiation technique. The synthesized Schiff base ligand was then reacted with four transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) in 1:1 molar ratio of ligand and metal acetate using microwave technique. The stereochemistry and the bonding characteristics of the ligand and its metal complexes were achieved based on elemental analysis, FT-IR, UV-Vis., NMR and ESR as well as Thermo-Gravimetric Analysis (TGA). The thermal dehydration and decomposition of Co (II), Ni(II) and Cu(II) complexes were studied kinetically using the integral method applying the Coats-Redfern and Horowitz Metzger equations. The antimicrobial activities of ligand and its Zn (II) complex were studied against the bacterial (positive and negative) grams and fungal strains.