The kinetics of the reactions of picryl chloride with some substituted anilines. Part 7. 2-Substituted and 2,5-disubstituted anilines

Abstract

Arrhenius parameters have been measured for the reactions of picryl chloride with the following substituted anilines in acetonitrile: 2-X (X = F, Cl, Br, l, Me, or OMe); 2,5-X₂(X = Cl, Br, Me, or OMe); 2-X-5-NO₂(X = F, Cl, Me, or OMe). Steric effects are shown to be present in the reactions of the 2-substituted series. In the disubstituted series the effect of 2,5-dimethyl and 2-methoxy-5-nitro-groups on the free energy of activation is strictly additive, but for the rest the measured rate constants are less than those calculated on the assumption of additivity. The results are consistent with a previously proposed explanation of deviation of substituent effects from additivity.