| In this paper, the kinetics and mechanism of oxidation of polyhydric alcohol, glutamic acid, sodium glycollate by dihydroxyditelluratoargentate(III) dihydroxydipriodato-argentate(III) ? ,dihydroxytelluratocuprate(III) was studied respectively by spectrophoto-metrically in alkaline medium. Based on our study, [Ag(OH)2(H4TeO6)2]3-,[Ag(OH)2(H2IO6)2]5- [Cu(OH)2(H4TeO6)2]3- were the existent form in the alkaline medium, and the activation center was [Ag(OH)2(H3TeO6)]2-,[Ag(OH)2(HIO6)]3-,[Cu(OH)2(H3TeO6)]2- respectively. Through the experimentation, we find that the reaction rate changed with the mechanism of the reaction and the position of hydroxyl group and the number of activity group. From the reaction of polyhadric alcohol oxidation by dihydroxyditelluratoargentate(III), At the same temperature, the reaction rate constant of the determining-step has such a sequence: propanetriol>1,2–propanediol>1,3-propanediol, which induce the reaction rate was decreased. In the system of diethylene glycol, the reaction rate is larger than propanetriol's, because the different reaction mechanism. In the reaction system of dihydroxydipriodatoargentate(III) and glutamic acid, we brought forward the two different mechanism because of the alkaline value. There is free radical in the reaction of ditelluratocuprate(III) and sodium glycollate, so we concluded the reaction mechanism which is different from other reaction system above. The supposed mechanism can favorably explain the reaction results. Meanwhile, the determining-step rate constants (k) and activation parameters were obtained at 298.2K. The hypothesis that the complex was existed as the deprotonated form was supported by our experimental results. From the macroscopical experimentation phenomena, we can explain the microstructure of the complex, and conjecture the stability and structure of the transition... |
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