碱性介质中二(过碲酸)合银(Ⅲ)离子氧化苹果酸的动力学及机理  

Kinetics of Oxidation of Malic Acid by Ditelluratoargentate(Ⅲ) Ion in Alkaline Medium

作　　者：单金缓[1] 王莉[1] 申世刚[1] 刘保生[1] 孙汉文[1] 

机构地区：[1]河北大学化学与环境科学学院,河北保定071002

出　　处：《河北大学学报（自然科学版）》2001年第1期53-56,共4页Journal of Hebei University(Natural Science Edition)

基　　金：河北省自然科学基金资助项目! (2 95 0 6 6 )

摘　　要：在 2 5～ 4 0℃区间内用分光光度法在碱性介质中研究了二 (过碲酸 )合银 (Ⅲ )离子氧化苹果酸的动力学及机理 .实验结果表明反应对二 (过碲酸 )合银 (Ⅲ )离子是准一级的 ,对苹果酸是分数级 .准一级速率常数kobs随 [OH- ]及 [TeO2 - 2 ]的增大分别减小 ,且发现有正的盐效应 .根据实验结果 ,提出了包含有双电子转移的反应机理 ,据此导出了一个能解释全部实验事实的速率方程 ,并求出了速控步的速率常数及 2 5℃时的活化参数 .The kinetics of oxidation of malic acid by ditelluratoargentate(Ⅲ) ion was studied by spectrophotometry in alkaline medium. The reaction rate showed first order dependence on Ag(Ⅲ)and positive fractional order dependence on malic acid.k obs decreased with the increase in [OH-][TeO 2- 4] respectively. The active species and a plausible mechanism involving two-electron transfer have been proposed .All the experimental phenomena can be explained by the rate equation derived from the mechanism. The rate constants of the rate-determining step together with the activation parameters have also been calculated

关 键 词：二(过碲酸)合银离子 苹果酸 氧化还原 动力学 双电子转移 反应机理 盐效应 

分 类 号：O643.12[理学—物理化学] O614.122.6[理学—化学]