Abstract
Charge-transfer complexes formed between norfloxacin (nor) or ciprofloxacin (cip) drugs as donors with picric acid (PA) and/or 3,5-dinitrobenzoic acid (DNB) as π-acceptors have been studied spectrophotometrically in methanol solvent at room temperature. The results indicated the formation of CT-complexes with molar ratio1:1 between donor and acceptor at maximum CT-bands. In the terms of formation constant (
K
CT), molar extinction coefficient (
ε
CT), standard free energy (Δ
G
o), oscillator strength (
f), transition dipole moment (μ), resonance energy (
R
N) and ionization potential (
I
D) were estimated. IR, H NMR, UV–Vis techniques, elemental analyses (CHN) and TG–DTG investigations were used to characterize the structural of charge-transfer complexes. It indicates that the CT interaction was associated with a proton migration from each acceptor to nor or cip donors which followed by appearing intermolecular hydrogen bond. In addition, X-ray investigation was carried out to scrutinize the crystal structure of the resulted CT-complexes.