Spectroscopic, thermal and kinetic studies of coordination compounds of Zn(II), Cd(II) and Hg(II) with norfloxacin

Some metal complexes of norfloxacin (NOR) with the formula [M(NOR)(2)]X(2)center dot nH(2)O [M = Zn(II), (X = Cl(-), AcO(-), Br(-) and I(-)), Cd(II), (X = Cl(-), NO(3) (-) and SO(4) (2-)) and Hg(II) (X = Cl(-), NO(3) (-) and AcO(-))] have been synthesised and studied using elemental analysis (CHN), electronic (UV-vis, mid infrared, mass, and (1)H-NMR spectra), TG and DTA. The thermal decomposition processes of these complexes were discussed. The Correlation coefficient, the activation energies, E*, the pre-exponential factor, A, the entropies, S*, enthalpies, H* and Gibbs free energies, G*, of the thermal decomposition reactions have been derived from thermogravimetric (TG) and differential thermogravimetric (DTG) curves. The characterization of the final products of the decomposition was achieved by IR spectra and X-ray powder diffraction (XRD). Using the Coats-Redfern and Horowitz-Metzeger methods, kinetic analysis of the thermogravimetric data is performed.