Antimicrobial Applications of Transition Metal Complexes of Benzothiazole Based Terpolymer: Synthesis, Characterization, and Effect on Bacterial and Fungal Strains

Abstract

Terpolymer of 2-amino-6-nitro-benzothiazole-ethylenediamine-formaldehyde (BEF) has been synthesized and characterized by elemental analysis and various spectral techniques like FTIR, UV-Visible, and1H and13C-NMR. The terpolymer metal complexes were prepared with Cu2+, Ni2+, and Zn2+metal ions using BEF terpolymer as a ligand. The complexes have been characterized by elemental analysis and IR, UV-Visible, ESR,1H-NMR, and13C-NMR spectral studies. Gel permeation chromatography was used to determine the molecular weight of the ligand. The surface features and crystalline behavior of the ligand and its complexes were analyzed by scanning electron microscope and X-ray diffraction methods. Thermogravimetric analysis was used to analyze the thermal stability of the ligand and its metal complexes. Kinetic parameters such as activation energy(Ea)and order of reaction (n) and thermodynamic parameters, namely,ΔS,ΔF,S*, andZ, were calculated using Freeman-Carroll (FC), Sharp-Wentworth (SW), and Phadnis-Deshpande (PD) methods. Thermal degradation model of the terpolymer and its metal complexes was also proposed using PD method. Biological activities of the ligand and its complexes were tested againstShigella sonnei,Escherichia coli,Klebsiellaspecies,Staphylococcus aureus,Bacillus subtilis, andSalmonella typhimuriumbacteria andAspergillus flavus,Aspergillus niger,Penicilliumspecies,Candida albicans,Cryptococcus neoformans,Mucor speciesfungi.