Kinetics and mechanism of oxidation of 1,2-butanediol by argentate(III) complex in alkaline medium

The kinetics of oxidation of 1,2-butanediol by dihydroxyditellutoargentate(III) (DDA) is studied spectrophotometrically. The reaction rate shows first order dependence in DDA and 1 < n(ap) < 2 order in 1,2-butanediol. It is found that the pseudo-first order rate constant k(obs) increases with the increase in concentration of OH- and decreases with the increase in concentration of TeO42-. There is a negative salt effect; no free radical is detected. In view of this, the dihydroxymonotelluratoargentate(III) species is assumed to be the active species. A plausible mechanism involving a two-electron transfer is proposed and the rate equations derived from mechanism explains all experimental results. The activation parameters along with the rate constants of the rate-determining step are calculated.