Complexation and thermogravimetric investigation on tin(II) and tin(IV) with norfloxacin as antibacterial agent

Abstract

The interaction of tin(II) and tin(IV) chlorides with norfloxacin (NOR) has been investigated. Elemental analysis, infrared, mass spectra and thermal analysis have been used to characterize the isolated solid complexes. The results support the formation of complexes with the formula [Sn(NOR)₂]Cl₂·4H₂O and [Sn(NOR)₃]Cl₄. The infrared spectra of the isolated solid complexes suggested that NOR act as bidentate ligand through the carbonyl oxygen atom and one oxygen atom of the carboxylic group forming six-membered rings with the tin ions. The interpretation, mathematical analysis and evaluation of kinetic parameters of thermogravimetric (TGA) and its differential (DTG), such as entropy of activation, pre-exponential factors, activation energy evaluated by using Coats–Redfern and Horowitz–Metzger equations are carried out for two complexes. The data obtained indicate that the two complexes decompose in one stage and general mechanisms describing the decomposition are suggested. Furthermore, the electronic, and ¹H NMR spectra have been studied.

Keywords:

• Tin chlorides
• Norfloxacin
• Thermal analysis
• ¹H NMR spectra