Spectrophtometric Study of Catalysed Oxidation of Some Cyclic Alcohols by N-bromophthalimide

Abstract

The spectrophotometric kinetic investigation of cyclohexanol and cycloheptanol catalysed by Keggin type anion [PW12O40]3- with N-bromophthalimide have been carried out in 30% acetic acid medium in absence of mercuric(II) acetate and in presence of sulphuric acid. The observed kinetic data was used for the justification of Beer-Lambert law. The reactions follow a fractional-order with respect to cyclic alcohols, PTA catalyst and first-order with respect to oxidant NBP. The added H+ ion did not affect the reaction rate. Increases in percentage of acetic acid, increased the rate of reaction. The redox reaction fails to initiate polymerization with acrylonitrile (monomer) and free radical based mechanism is ruled out. A complex mechanism with stoichiometric ratio 1:1 was proposed and order of reactivity was discussed. The rate law was formulated in good agreement with the observations and activation parameters. Keywords : Justification, redox, complex, acrylonitrile, cyclic alcohols.