Substituent effects in the reaction of aromatic amines and peroxydisulfate

Abstract

The kinetics of the reaction between aromatic amines and the peroxydisulfate ion in aqueous basic conditions have been investigated. The effect of substituents has been studied by employing about 25 ortho-, meta-, and para-substituted anilines. The reaction is accelerated by electron-releasing substituents and is retarded by electron-withdrawing substituents, pointing to an electrophilic attack by the S2O82− ion. A better correlation between rate and the Hammett constants is obtained for an electrophilic attack at the nitrogen atom of the amine rather than at the carbon atom of the amine. A good correlation also exists between the log k2 values and the pKb of the corresponding amines.