Effect of Substituents on Kinetics of Phenols by Pyridinium Fluorochromate in Glacial Acetic Acid

Abstract

The effect of substituents on the reaction rate for oxidation   of phenol by pyridinium fluorochromate has been investigated   in glacial acetic acid at 303 and 308 K by ploting log k₂   vs. 6_x. From the slope of the resulting straight line, the values   of ‘ρ’ were calculated. The negative ‘ρ’ values in the reaction   indicating the development of +ve charge at the reaction. The   reaction is thus accelerated by electron donating substituents,   which help to delocalize the +ve charge in the intermediate   complex and correspondingly retarted by electron-withdrawing   substituents. The Hammett treatment has been applied to these   reactions and to different functional groups.