高等学校化学学报

高等学校化学学报

• 研究论文 • 上一篇    下一篇

1,4-与1,2-二氢NADH模型物反应活性的比较

焦晓云, 章名田, 朱晓晴, 程津培   

  1. 南开大学化学系, 元素有机化学国家重点实验室, 天津 300071
  • 收稿日期:2007-10-22 修回日期:1900-01-01 出版日期:2008-06-10 发布日期:2008-06-10
  • 通讯作者: 程津培

Comparison of the Reactivity Between 1,4- and 1,2-Dihydro NADH Models

JIAO Xiao-Yun, Zhang Ming-Tian, ZHU Xiao-Qing, CHENG Jin-Pei*   

  1. State Key Laboratory of Elemento-Organic Chemistry, Department of Chemistry, Nankai University, Tianjin 300071, China
  • Received:2007-10-22 Revised:1900-01-01 Online:2008-06-10 Published:2008-06-10
  • Contact: CHENG Jin-Pei

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被引次数

1

摘要： 合成了两类NADH模型物: p-G-1,4-2H-PNAH和p-G-1,2-2H-PNAH, 测得了它们在不同温度下的乙腈中分别与四氯苯醌及N,N,N',N'-四甲基对苯二胺自由基正离子(TMPA+·)反应的速率常数及反应的活化参数(ΔH≠, ΔS≠, ΔG≠). 动力学研究结果表明: 1,2-2H-PNAH和1,4-2H-PNAH的相对反应活性可以通过远位取代基调节; 1,2-2H-PNAH和1,4-2H-PNAH与四氯苯醌的反应是决速步骤的熵控反应, 而1,2-2H-PNAH和1,4-2H-PNAH与TMPA+·的反应决速步骤则是由焓和熵共同控制的反应; 通过lnk2~σ的相关分析可以看出1,2-2H-PNAH和1,4-2H-PNAH与四氯苯醌及TMPA+·反应决速步骤中反应中心是正电荷增加的过程, 而且1,2-2H-PNAH的取代基效应大于1,4-2H-PNAH的取代基效应.

关键词: NADH模型物, 键离解能, 动力学, 热力学

Abstract: Two series of NADH models: p-G-PNAH-1,4-2H and p-G-PNAH-1,2-2H are synthesized. The rate constants at different temperatures and the activation parameters for the reaction of two oxidants(p-chloranil and TMPA+·) with these NADH models were determined in acetonitrile. The kinetics results reveal that the reactivity of 1,2-2H-isomer and 1,4-2H-isomer can be controlled by the remote substitutions. The reaction between GPNAH and p-chloranil was controlled by entropy while the reaction between GPNAH and TMPA+· was controlled by enthalpy and entropy together. And the substituted effect of 1,2-2H-isomer is bigger than 1,4-2H-isomer.

Key words: NADH model, Bond dissociation energy, Kinetics, Thermodynamics

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