Kinetics and mechanism of oxidation of aldehydes by t-butyl hypochlorite in aqueous acetic acid medium

Department of Post-Graduate Studies and Research in Chemistry, Mangalore University,

Mangalagangothri-574 199, India

Department of Chemistry, Canara College, Mangalore-575 003, India

Manuscript received 6 May 1996. revised 6 September 1999, accepted 26 November 1999

Kinetics of oxidation of formaldehyde, acetaldehyde, propionaldehyde and butyraldehyde by t-butyl hypochlorite have been investigated in aqueous acetic acid at 308 K. The reactions show first order kinetics in [t-BuOCI], fractional order in [aldehyde] and zero order in [H⁺]. Variation in ionic strength of the medium and addition of reduced products, t-butyl alcohol (0-0.05 mol dm^-3) have negligible effects on the rate, while lowering of dielectric constant of the medium by the addition of AcOH {20-60%, v/v) decreases the rate. Competitive mechanism involving substrate independent and dependent pathways has been suggested. The constancy of the rate coefficient for the substrate independent paths provides evidence for the proposed mechanism.