Macromolecular Azo Dye Complexes as Precursors to Metal Oxide Nanoparticles: Synthesis, Characterization, Biological Activity and Thermal Studies of Sulfadimidine Azo Dye Complexes

Abstract

Two azo dyes, L¹ and L² were synthesized from hydroxyl naphthoic acids and sulfadimidine drug. These azo dyes were characterized by elemental analyses, mass, IR and ¹H-NMR spectra. A series of Ni(II), Cu(II), Zn(II) and Pd(II) complexes were prepared with azo dyes, L¹ and L². The mode of chelation of the complexes has been proposed in the light of many analytical tools such as elemental analyses, UV-Vis, IR, magnetic moment measurements, ESR and thermal studies. The measured molar conductance values indicate that the complexes are non-electrolytes. The thermal decomposition kinetics of the complexes of L¹ was estimated by Coats-Redfern equation. The azo dye L¹ complexes with Ni(II) and Cu(II) ions are thermally decomposed in solid state at 600 ^oC for 2 hours. Synthesized nanoparticles have been characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that NiO and CuO nanoparticles can be prepared using Ni(II)-L¹ and Cu(II)-L¹ complexes with high purity. The azo dyes and their complexes have been screened for their antibacterial activity against Escherichia coli as gram negative and Staphylococcus aureus as gram positive bacteria.