Synthesis, Characterization and Biological Activity: Co(II), Ni(II), Cu(II) and Zn(II) Complexes of Schiff Bases Derived from 4-Cyanobenzaldehye and 4-Amino-5-Mercapto-3-Methyl/Ethyl-1,2,4-triazoles

Abstract

Co(II), Ni(II), Cu(II) and Zn(II) complexes of bidentate Schiff bases derived from the condensation of 4-amino-5-mercapto-3-methyl-1,2,4-triazole and 4-amino-3-ethyl-5-mercapto-1,2,4-triazole with 4-cyanobenzaldehyde have been synthesized. The synthesized Schiff bases and their metal complexes were then characterized by elemental analysis, spectroscopic methods (IR, NMR, electronic spectra), magnetic moment measurement and thermogravimetric techniques. The electronic spectra and magnetic moment studies suggest octahedral geometry for Co(II), Ni(II) and Zn(II) complexes and square planar geometry for Cu(II) complexes. The newly synthesized Schiff bases and their metal complexes were screened against bacteria (Bacillus pumilus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli) and fungi (Aspergillus niger and Penicillium).
Keywords: 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazoles, Schiff bases, Metal complexes, Antimicrobial activity, Thermal study