KINETICS AND MECHANISM OF OXIDATION OF BISTYRYL KETONES BY QUINOLINIUM FLUOROCHROMATE

摘要

The kinetics of oxidation of substituted styryl ketones (dibenzalacetone and substituted)by quinolinium fiuorochromate (QFC)has been studied in aqueous acetone media in the presence of 1,10-phenanthroline (Phen)under pseudo-first order conditions.The reaction order is one with respect to oxidant,substrate and catalyst,and fractional order with respect to H+ion.The reaction rates are enhanced by electron-releasing substituents in the both phenyl rings and decreased by electron-withdrawing substituents.Linear Hammett's plots are observed for various substituents in benzaldehyde moiety of styryl ketone.An epoxide is isolated as the product of oxidation.From the kinetic data obtained,the activation parameters have been calculated and a plausible mechanism has been proposed.