Kinetics and Mechanism of the Oxidation of Glycol by Dihydroxyditelluratoargentate(Ⅲ) with Spectrophotometry

The kinetics of the oxidation of glycol by dihydroxyditelluratoargentate (Ⅲ) complex(DDA) was studied in alkaline medium with spectrophotometry(in a temperature range of 16.6-40 ℃).The first-order rates with respect to glycol and Ag(Ⅲ) were all found.The rates increased with the increase in [OH-] and decreased with the increase in [TeO2-4].No effect was found with the addition of KNO3 and no free radical was detected.In view of this,the dihydroxymonotelluratoargentate(Ⅲ) species(DMA) is assumed to be the active species.A plausible mechanism involving a two-electron transfer is proposed,and the rate equation derived from the mechanism can explain all experimental observations.Activation parameters of the rate-determining step and constants are evaluated.