Synthesis, thermogravimetric analysis, infrared, electronic and mass spectra of Mn(II), Co(II) and Fe(III) norfloxacin complexes

The interactions of manganese acetate, ferric chloride and cobalt sulphate with norfloxacin (NOR) in acetone or methanol were studied. The isolated solid complexes were characterized by elemental analysis, infrared, electronic, mass spectra and thermal analysis. The results support the formation of complexes of the formula [Fe(NOR)3]Cl3·12H2O and [M(NOR)2]X2·8H2O (M=Mn(II) or Co(II) and X=(CH3COO−) or SO4−2). The infrared spectra of the isolated solid complexes suggested, indicated that NOR act as bidentate ligands through one of the oxygen atoms of the carboxylic group and the ring carbonyl oxygen atom. 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 for two complexes are carried out. General mechanisms describing the decomposition of the solid complexes are suggested.