IR, 1H NMR, mass, XRD and TGA/DTA investigations on the ciprofloxacin/iodine charge-transfer complex

Abstract

The charge-transfer complex (CTC) of ciprofloxacin drug (CIP) as a donor with iodine (I 2) as a sigma acceptor has been studied spectrophotometrically in CHCl 3. At maximum absorption bands, the stoichiometry of CIP:iodine system was found to be 1:1 ratio according to molar ratio method. The essential spectroscopic data like formation constant ( K CT ), molar extinction coefficient ( ɛ CT ), standard free energy (Δ G°), oscillator strength ( f), transition dipole moment ( μ), resonance energy ( R N ) and ionization potential ( I D ) were estimated. The spectroscopic techniques such as IR, 1H NMR, mass and UV–vis spectra and elemental analyses (CHN) as well as TG-DTG and DTA investigations were used to characterize the chelating behavior of CIP/iodine charge-transfer complex. The iodine CT interaction was associated with a presence of intermolecular hydrogen bond. The X-ray investigation was carried out to investigate the iodine doping in the synthetic CT complex.