Structural and chelation behaviors of new Ru(II), Pt(IV) and Ir(III) gatifloxacin drug complexes: Spectroscopic characterizations

The interaction between gatifloxacin drug (GAT) with some transition metals (Ru(III), Pt(IV) and KM)) yield the complexes of formulas [Ru(GAT-NH4)(Cl)(3)(H2O)(2)], [Pt(GAT-NH4)(2)(Cl)(4)]center dot 3H(2)O and [Ir(GAT-NH4)(2)(Cl)(2)(H2O)(2)]center dot Cl center dot 2H(2)O at pH = 7-8. The composition of the GAT complexes was confirmed by elemental data. The IR frequencies reveal the coordination of the GAT with metal ions and the coordination mode of the -N atom of 3-methylpiperazinyl moiety to metal. XRD pattern show isomorphism among the complexes with similar chelation behavior. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to identify the particle size of GAT complexes. The thermal data reveals that various steps of decomposition of the complexes to form their metal oxide as final product. The electronic spectra and the magnetic susceptibility values reveal that the coordination and geometry of Ru3+, Pt4+ and Ir3+ complexes possess distorted octahedral geometry with six number of coordination. Thermodynamic parameters (E*, Delta S*, Delta H* and Delta G*) were calculated from TG curves dependent on Coats-Redfern and Horowitz-Metzeger non-isothermal methods. (C) 2016 Elsevier B.V. All rights reserved.