摘要
The kinetics of the oxidation of 1,2-butanediol or mephenesin by ditelluratocuprate(Ⅲ)(DTC) was investigated spectrophotometrically at temperatures between 283.2―303.2 K in alkaline media. The reaction rate showed first order dependence in DTC and fractional order in 1,2-butanediol or mephenesin. It was shown that the pseudo- first-order rate constant kobs increased with an increase in concentration of OH– and a decrease in concentration of TeO42–. The reaction has a negative salt effect. A plausible mechanism of reaction involving a pre-equilibrium of adduct formation between the complex and 1,2-butanediol or mephenesin was proposed. The rate equations derived from the mechanism can explain all the experimental phenomena. The activation parameters for the rate-determining step were also calculated.
The kinetics of the oxidation of 1,2-butanediol or mephenesin by ditelluratocuprate(Ⅲ)(DTC) was investigated spectrophotometrically at temperatures between 283.2―303.2 K in alkaline media. The reaction rate showed first order dependence in DTC and fractional order in 1,2-butanediol or mephenesin. It was shown that the pseudo- first-order rate constant kobs increased with an increase in concentration of OH– and a decrease in concentration of TeO42–. The reaction has a negative salt effect. A plausible mechanism of reaction involving a pre-equilibrium of adduct formation between the complex and 1,2-butanediol or mephenesin was proposed. The rate equations derived from the mechanism can explain all the experimental phenomena. The activation parameters for the rate-determining step were also calculated.
基金
Supported by the Natural Science Foundation of Hebei Province,China(No.295066)