Kinetics and Mechanism of Oxidation of Benzaldehydes by Quinolinium Chlorochromate

Post-Graduate Department of Chemistry, Jamal Mohamed College, Tiruchirappalli-620 020 Manuscript received 28 November 1997, accepted 23 March 1998 The kinetics of oxidation of benzaldehyde (BA) and several para- and meta-substituted benzaldehydes to the corresponding benzoic acids by quinolinium chlorochromate (QCC) have been studied. The reaction is first order each in (QCC), (substrate) and (H+). The reaction rates have been determined at different temperatures and the activation parameters calculated. The rate decreases with an increase in the amount of acetic acid in its aqueous mixture. Addition of acrylonitrile induces polymerization. The rates of the reactions have been analysed in terms of Taft's dual substituent parameter equation. Suitable mechanism has been proposed