Cross effects of structure and temperature in the reactions of trans-2,3-diaryloxiranes with arenesulfonic acids

Resumo

Cross effects of the reagent structure and the temperature on the rate and activation parameters of the reactions of symmetrically X-substituted trans-2,3-diaryloxiranes with Y-substituted arene-sulfonic acids have been investigated in the temperature range 265–298 K. The isokinetic temperature of 265 K was reached, at which the rate and the free energy of the ring-opening reaction of trans-2,3-bis(3-bromo-5-nitrophenyl)-oxirane practically do not depend on substituent Y. The transition through the isoparametric points on substituent Y was realized with the inversion of the temperature effect on the free energy of activation for the reactions of oxiranes with X = 4-NO₂ and 3-Br-5-NO₂.