碱性介质中二过碘酸合铜（Ⅲ）配离子氧化氨基乙酸的反应动力学

本文用分光光度法研究了碱性介质中二过碘酸合铜（Ⅲ）配离子氧化氨基乙酸的反应动力学。实验结果表明反应对Ｃｕ（Ⅲ）是准一级。表观速率常数ｋｏｂｓ随着氨基乙酸浓度的增加而增大，随着〔ＯＨ－〕的增大而增大，但随着〔ＩＯ－４〕的增大反而减小；且发现１／ｋｏｂｓ对〔氨基乙酸〕和１／ｋｏｂｓ对〔ＩＯ－４〕有线性关系。据此提出了一种含有前期平衡的反应机理，推出了一个能够解释全部实验事实的速率方程式，求得了速控步骤的速率常数ｋ，并给出了相应的活化参数。

Kinetics and Mechanism of Oxidation of Aminoacetic Acid by Diperiodatocuprate(Ⅲ) Complex in Alkaline Medium

The kinetics of oxidation of aminoacetic acid by diperiodatocuprate(Ⅲ) comples ion was studied by spectrophotometry in alkaline medium. The reaction rate showed first order dependance in oxidant. It was found that the pesudo-first-order (》) rate costant k obs increases with the increase in and increases with the increase in OH - , but decreases with the increase in . Linear relationships between 1/k obs and 1/ and between 1/k obs]and IO - 4 were observed. There is a neagative salt effect. A plausible mechanism involving free redical has been proposed. The rate equations derived from the mechanism explained all the experimental results satisfactorily. The rate constants and activation parameters of the rate determining step are 2.73×10 -2 s -1 (297.2K), 5.43×10 -2 s -1 (301.2K), 6.96×10 -2 s -1 (303.2K), Ea=100.39kJ·mol -1 , △S -=141.25J·K -1 mol -1 , at 298K respectively.