OXIDATION OF NEOPENTYL GLYCOL AND 1,3-BUTANEDIOL BY DITELLURATOCUPRATE(III) IN ALKALINE MEDIUM. A KINETIC AND MECHANISTIC STUDY

摘要

The kinetics of oxidation of neopentyl glycol and 1,3-butanediol by ditelluratocuprate(III) (DTC) in alkaline medium has been studied spectrophotometrically in the temperature range of 20-40 degrees C. All data were obtained under the conditions of pseudo-first order reaction in [DTC]. It was found that the reaction had fractional order in [neopentyl glycol] and first order in [1,3-butanediol]. Increasing [OH-] and [reductant], the rate constant k(obs) increased, however, k(obs) decreased with increase in [TeO42-]. In addition, the reaction in [neopentyl glycol] has a negative salt effect, but the reaction in [1,3-butanediol] has a positive salt effect. It was experimentally found that the rate of oxidation of neopentyl glycol was higher than that of 1,3-butanediol. The reaction constants of the different steps of the mechanism were calculated. Activation parameters which controlled by slow step of the mechanism were discussed and thermodynamic quantities determined. Thus, the activation parameters at 298.2 K were calculated.