A sensitive spectrophotometric method was employed to study the charge transfer complex of chloranil with 6-(trifluoromethyl)furo[2, 3-b]pyridine-2-carbohydrazide derivatives (TFC). The method is based on the reaction of these drugs as n-electron donors with the pi-acceptor 2,3,5,6-tetrachloro-1,4-benzoquinone. The obtained coloured charge transfer complex was measured at 412 nm by UV-Vis spectrophotometer. The obtained complexes were confirmed by 1H NMR and IR spectral analysis. The proposed procedure could be applied successfully to the determination of the association constants and standard free energy changes using Benesi-Hildebrand plots.
Charge transfer complex, Chloranil, Association constant, Gibbs free energy