Thiazole‐Based Novel Terpolymer Ligand and Its Transition Metal Complexes: Thermal and Biological Studies

Abstract

ABSTRACTA new terpolymer ligand involving 2‐amino‐6‐nitro‐ benzothiazole, melamine, and formaldehyde (BMF) has been synthesized in the presence of dimethyl formamide medium. The BMF ligand was characterized by elemental analysis and various spectral techniques like Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV)–visible spectroscopy, and 1H & 13C nuclear magnetic resonance (NMR) spectroscopy to elucidate the structure and properties of the terpolymer ligand. The BMF metal complexes were prepared using the BMF ligand with some transition metal ions, such as Cu2+, Ni2+, and Zn2+ ions, in the presence of ethanol medium. The prepared complexes have been characterized by elemental analysis and FTIR, electronic, electron spin resonance, and 1H & 13C NMR spectral studies. The molecular weight of the BMF ligand and its metal complexes was determined by gel permeation chromatography. The surface features and crystalline behavior of the ligand and its complexes were analyzed by scanning electron microscope (SEM) and X‐ray diffraction (XRD) methods. Thermal stability of the ligand and its metal complexes was studied by thermogravimetric analysis (TGA). Kinetic parameters such as activation energyand order of reaction (n), and thermodynamic parameters namely entropy change, free energy change, apparent entropy, and frequency factor were calculated using Freeman–Carroll, Sharp–Wentworth, and Phadnis–Deshpande (PD) methods. Thermal degradation model of the terpolymer ligand and its metal complexes was also proposed using the PD method. The antibacterial activities of the BMF ligand and its metal complexes were checked against chosen microbes such as Shigella sonnei, Escherichia coli, Klebsiella species, Staphylococcus aureus, Bacillus subtilis, and Salmonella typhimurium. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2013, 32, 21376; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21376