Abstract
The charge-transfer (CT) interactions between the electron donor sulfasalazine (SS) and the acceptors 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), p-chloranil (CHL), picric acid (PA) and iodine have been studied spectrophotometrically in CHCl3 or CH3OH solutions. The formed solid CT complexes were also isolated and characterized through infrared, H-1-NMR, mass spectra as well as elemental and thermal analysis. The CT complexes were discussed in terms of formation constant (K-CT), molar extinction coefficient (epsilon(CT)), standard free energy (Delta G degrees), oscillator strength (f), transition dipole moment (mu), resonance energy (R-N) and ionization potential (I-D). The stoichiometry of these complexes was found to be 1 : 1 molar ratio and having the formulae [(SS)(DDQ)], [(SS)(CHL)], [(SS)(PA)] and [(SS)(2)I](+,) I-3(-), respectively. The charge transfer interaction was successfully applied to the determination of SS drug using mentioned alpha and pi-acceptors also, the results obtained herein are satisfactory for estimation of SS compound in the pharmaceutical form. Copyright (c) 2010 John Wiley & Sons, Ltd.