高等学校化学学报

高等学校化学学报 ›› 2002, Vol. 23 ›› Issue (10): 1860.

• 研究论文 • 上一篇    下一篇

分光光度法研究二羟基二过碘酸合镍(Ⅳ)氧化三乙醇胺的反应动力学及机理

单金缓, 魏海英, 王莉, 申世刚, 刘保生, 孙汉文, 王安周   

  1. 河北大学化学与环境科学学院, 保定 071002
  • 收稿日期:2001-07-02 出版日期:2002-10-24 发布日期:2002-10-24
  • 通讯作者: 单金缓(1960年出生),女,硕士,教授,从事液相化学反应动力学研究.
  • 基金资助:

    河北省自然科学基金(批准号:295066)资助

Kinetics and Mechanism of Oxidation of Triethanolamine by Diperiodatonickelate(Ⅳ) Ion in Aqueous Medium

SHAN Jin-Huan, WEI Hai-Ying, WANG Li, SHEN Shi-Gang LIU Bao-Sheng, SUN Han-Wen, WANG An-Zhou   

  1. College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China
  • Received:2001-07-02 Online:2002-10-24 Published:2002-10-24

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被引次数

22

摘要： 在碱性介质中,用分光光度法研究了二羟基二过碘酸合镍(Ⅳ)配离子氧化三乙醇胺的动力学.结果表明,反应对Ni(Ⅳ)为准一级反应,速率常数kobs=(k1+k2[OH-])K1K2[OH-][TEA]/{[H2IO63-]+K1[OH-]+K1K2[OH-][TEA]},对还原剂三乙醇胺为正非整数级,表观速率常数随[OH-]的增加而增加,随[IO4-]的增加而减小.据此提出了Ni(Ⅳ)和还原剂所形成的活化配合物的内部电子转移的反应机理.并求得28℃时前期平衡常数和速控步骤的速率常数分别为K1=2.063,K2=36.471L·mol-1;k1=8.008×10-2s-1,k2=0.2896mol-1·L·s-1.

关键词: 二羟基二过碘酸合镍(Ⅳ), 三乙醇胺, 氧化还原, 动力学及机理

Abstract: The kinetics of oxidation of triethanolamine by dihydroxydiperiodatonickelate(Ⅳ) ion(DPN) was studied by spectrophotometry in aqueous medium. The reaction was found to be pseudo-first order with respect to Ni(Ⅳ) and to be fractional order with respect to triethanolamine. The rate increased with the increase of the concentration of OH- and decreased with the increase of the concentration of IO4-. The observed rate constants: kobs=(k1+k2[OH-])k1k2[OH-][TEA]/{[H2IO63-]+K1[OH-]+k1k2[OH-][TEA]}. Based on these, a mechanism involving the form of activative complex between Ni(Ⅳ) and reduct(TEA) was proposed. In addition, we calculated the equilibrium constants and rate-determining constants at 28 ℃, which were k1=8 008×10-2s-1, k2=0 289 6 mol-1·L·s -1, K1=2 063 and K2=36 471 L·mol -1.

Key words: Dihydroxydiperiodatonickelate(Ⅳ), Triethanolamine, Redox reaction, Kinetics and mechanism

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