Dewar reactivity number (original) (raw)

In Hückel theory, a Dewar reactivity number, also known as Dewar number, is a measure of the reactivity in aromatic systems. It is used to quantify the difference in energy between the π-system of the original molecule and the intermediate having the incoming electrophile or nucleophile attached. It can be used to study important transformations such as the nitration of conjugated systems from a theoretical perspective. The method is particularly efficient for alternant hydrocarbons in which the coefficients of the non-bonding orbitals involved are very easy to calculate.