Interdependence of the Hammett and isokinetic relationships: a numerical simulation approach

Abstract

Many homologous reaction series present linear correlations between the enthalpy ( o ,i H   ) and entropy ( o ,i S  ) of activation (kinetic compensation effect), the slope being the isokinetic temperature of the series (T iso ), so that at T = T iso all the reactions of the family share the same value of the rate constant. S   vs. i  plots, are all indicative of false isokinetic relationships, highly contaminated by the statistical correlation between the enthalpy and entropy experimental errors.