Preferential solvation effects on the kinetics and thermodynamics of oxidation of anilines by chromium(VI)

The imidazolium fluorochromate (IFC) oxidation of fifteen meta- and para-substituted anilines, in varying mole fractions of benzene in 2-methylpropan-2-of as mixtures, in the presence of p-toluenesulfonic acid (TsOH) is first order in IFC and TsOH and zero order in substrate. The various thermodynamic parameters for the oxidation have been reported and discussed. The validity of the isokinetic relationship and various linear free energy relationships have been tested and discussed. The activation free energy data failed to correlate with macroscopic solvent parameters such as epsilon(r) and E-T(N). Correlation of Delta G(#) with Kamlet-Taft solvatochromic parameters (alpha, ss and pi*) suggests that the specific solute-solvent interactions play a major role in governing the reactivity.