Synthesis and Characterization of a New Bidentate Ligand 5-Substituted-(2-methyl-5-nitro-1-imidazomethyl)-1,3,4-oxadiazole-2-thione and its Metal Complexes of Ag(I), Cu(II) and Zn(II)

A new ligand (2-methyl-5-nitro-1-imidazomethyl)-1,3,4-oxadiazole-2-thione (L) and its Ag(I),Cu(II) and Zn(II) complexes were synthesized. The authenticity of the ligand and its transition metal complexes were established by elemental analyses, conductance and magnetic susceptibility measurements, as well as spectroscopic (IR, 1H NMR, electronic, mass and ESR) and thermal studies. The IR spectral studies revealed the existence thiol-thione tautamerism in the ligand molecule. The magnetic and electronic spectral studies suggest an octahedral geometry for Cu(II) and Zn(II) complexes. The ligand acts as a bidentate coordinating through the N-3 nitrogen and the exocyclic sulfur atoms of oxadiazole rings. Antimicrobial screening of the ligand and its metal complexes were determined against the bacteria Escherichia coli and Salmonella paratyphiA.