碱性介质中二羟基二过碘酸合镍(IV)配离子氧化天冬氨酸的反应动力学及机理  

Kinetics and mechanism of oxidation of aspartic acid by dihydrodiperiodatonickelate (IV) complex in alkaline aqueous medium

作　　者：单金缓[1] 魏海英[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,保定071002

出　　处：《河北省科学院学报》2001年第2期93-98,共6页Journal of The Hebei Academy of Sciences

基　　金：河北省自然科学基金资助项目(295066)

摘　　要：在碱性介质中于 ２０－３５℃用分光光度法研究了二羟基二过碘酸合镍（ＩＶ）配离子 （ＤＤＮ）氧化天冬氨酸的动力学。结果表明，反应对［Ｎｉ（ＩＶ）］为一级，对天冬氨酸为正分数级。准 一级速率常数（Ｋｏｂｓ）随［ＯＨ－］增加而减小，１／ｋｏｂｓ对［ｉｏ－４］有线性关系，表明二羟基一过碘酸合镍 （ＩＶ）配离子（ＤＭＮ）是氧化剂的活性物种。无盐效应且未检出自由基的存在。据此提出了包括 ＤＰＮ和ＭＰＮ以及天冬氨酸存在前期平衡的反应机理，并求出相应的活化参数。The kinetics of oxidation of aspartic acid by dihydrodiperiodatonickelate (IV) complex (DDN) was studies by spectrophotometry in aqueous medium in a temperature range of 20 - 35℃. The reaction was found to he first order with respect to[ Ni(IV)] and to be fractional order with re- spect to aspartic acid. The observation rate decreased with the increase both in [OH-] and [IO-4], showing that dihydromonoperiodatonickelate(IV) (DMN) is the reactive species ig oxidation. Added salts did not affect the rate. No free radical was detected. A mechanism of reaction involving preequi- libria both DDN and aspartic acid can explain all experimental observations. Activation parameters of the rate-determining step were calculated.

关 键 词：二过碘酸合镍 天冬氨酸 氧化 动力学 分光光度法 

分 类 号：O643.12[理学—物理化学] O614.813[理学—化学]