Quinoxaline-1,4-dioxide: Substituent effects on the N-O bond dissociation enthalpy

The effect of several different substituents on the mean N-O bond dissociation enthalpies of 2-substituted-quinoxaline-1,4-dioxides have been investigated by Density Functional Theory. For five selected cases the influence of electron and proton affinities and also of N-O bond dissociation enthalpies on the antitumor activity of selected compounds is analyzed.