Oxidation of N-methyldiethanolamine and N, N-dimethyl ethanolamine by ditelluratoar – gentate (iii) in alkaline medium. A kinetic and mechanistic study

Abstract

In the temperature range of 288.2K-308.2K, the oxidation reaction of N-methyldi ethanlamine and N, N-dimethyl ethanolamine with ditelluratoargentate (III)(DTA) in alkaline medium has been studied spectrophotometrically. The reaction rate showed fraction order in N-methyldiethanolamine and N,N-dimethyl ethanolamine. With the increase of [reductant] and [OH-], the rate constant kobs increased, but kobs decreased with the increase of [TeO42-]. It was clear that the rate of N-methyldiethanolamine is higher than that of N,N-dimethyl ethanolamine. In addition, there is a negative salt effect on the reaction of N,N-dimethyl ethanolamine and N-methyldiethanolamine, the influence of salt effect is not very obvious. A plausible mechanism involving a slow reaction as the rate-controlled step is proposed and the rate equations derived from the mechanism can explain all the experimental results. Thus, the activation parameters at 298.2K were calculated.