title: Spectrophotometric study of the charge-transfer complexes of iodine with antipyrine in organic solvents.
abstract: The charge-transfer complex formation of iodine with antipyrine has been studied spectrophotometrically in chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solutions at 25 degrees C. The results indicate the formation of 1:1 charge-transfer complexes. The observed time dependence of the charge-transfer band and subsequent formation of I(3)(-) in solution were related to the slow transformation of the initially formed 1:1 antipyrine:I(2) outer complex to an inner electron donor-acceptor (EDA) complex, followed by fast reaction of the inner complex with iodine to form a triiodide ion. The values of the equilibrium constant, K, are calculated for each complex and the influence of the solvent properties on the formation of EDA complexes and the rates of subsequent reaction is evaluated.
authors.affiliation: Department of Chemistry, College of Science, Bu-Ali Sina University, Hamadan 65174, Iran. hasani@basu.ac.ir
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Hasani
authors.forename: Alireza
authors.initials: A
authors.lastname: Rezaei
mesh_terms: D000983:Antipyrine / Q000737:chemistry*; D004347:Drug Interactions; D007455:Iodine / Q000737:chemistry*; D008954:Models, Biological; D012997:Solvents / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods
chemical_list: D012997:Solvents; D007455:Iodine; D000983:Antipyrine