RESEARCH ON KINETICS AND LFE RELATIONSHIP OF SUPERACID POSA CATALYZED ESTERIFICATION

From superacid POSA (perfluorooctanesulfonic acid) catalyzed esterification of p-substituted benzoic acids with ethanol, we got not only the rate canstants k, the energy of navigation Delta E, the entropy of activation Delta S*, and the enthalpy of activation Delta H-, but also a good Hammelt linear Free energy relationship (LFE Relationship). This is the first report of applying LFE relationship to superacid catalysis. Finally, the reaction intermediate, the reaction constant rho, and the mechanism of the reaction were also discussed. It is deduced by this paper that the mechanism of POSA catalyzed esterification is basically identical with those of normal strong acids catalysis, and the reaction is a process of general acid catalysis.