Study of charge transfer complexes of menadione (vitamin K3) with a series of anilines

Abstract Menadione (vitamin K 3 ) has been shown to form charge transfer complexes with N , N -dimethyl aniline, N , N -dimethyl p -toluidine and N , N -dimethyl m -toluidine in CCl 4 medium. The CT transition energies are well correlated with the ionisation potentials of the anilines. The formation constants of the complexes have been determined at a number of temperatures from which the enthalpies and entropies of formation have been obtained. The formation constants exhibit a very good linear free energy relationship (Hammett) at all the temperatures studied.