波谱学杂志 ›› 1998, Vol. 15 ›› Issue (2): 131-138.

• 研究论文 • 上一篇    下一篇

Pd(OAc)2与有机膦在氯代烷中的反应机理

韦凤萍1, 黄永仁1, 冯良波2, 汪汉卿2   

  1. 1 华东师范大学分析测试中心, 200062;
    2 中国科学院兰州化学物理研究所, 730000
  • 收稿日期:1997-11-28 出版日期:1998-04-05 发布日期:2018-01-13
  • 作者简介:韦凤萍,女,33岁,硕士,助研
  • 基金资助:
    国家自然科学基金资助项目

THE REACTION MECHANISM OF Pd(OAc)2 WITH PHOSPHINE IN CHLOROMETHANE

Wei Fengping1, Huang Yongren1, Feng Liangbo2, Wang Hanqing2   

  1. 1 Analytic center, East China Normal University, Shanghai 200062;
    2 Lanzhou Institute of Chemical Physics, Academia Sinica, Lanzhou 730000
  • Received:1997-11-28 Online:1998-04-05 Published:2018-01-13

摘要: 应用电子自旋捕获技术(EPR-ST)研究了Pd(OAc)2与有机膦dppm(二,二苯基膦甲烷)及dppe(二,二苯基膦乙烷)在氯代烷中反应生成新奇配合物PdCl2[PPh2CHClPPh2]这一新反应的反应机理,所用捕获剂为PBN和POBN,得到EPR实验谱并进行了模拟.提出了反应机理并进行了讨论.反应经过dppm的均裂、夺氯、夺氢后生成新配体[PPh2CHClPPh2],然后发生配位取代和配位反应,生成新的配合物PdCl2[PPh2CHClPPh2].并对影响反应的因素进行了探讨,溶剂效应在此类自由基反应中起重要作用,其极性对反应的发生影响很大,主要是对过渡态1及2的影响.Pd(OAc)2在反应中既是反应物还是引发剂,在反应中起分子诱导作用.

关键词: Pd(OAc)2, EPR-ST, 自由基, 氯代烷,

Abstract: The new reaction mechanism of Pd (OAc)2 with dppm or dppe in different chlorom ethane solvent was studied by EPR-ST method. The used capturer were PBN and POBN. The obtained experimental spectra were simulated. The free radicals·PPh2 and containing carbon free radicals were trapped in these experiments. The reaction mechanism was given and discussed. A new ligand PPh2CHClPPh2 was formed after the homolysis, the deprivation of chlorine and the deprivation of hydrogen. Then the substituted and complex reaction occurred between new ligand and Pd(OAc)2 to form a new complex PdCl2[PPh2CHClPPh2]. Some influence factors on the reaction were tentatively discussed. Solvent effects play an important role on the free radical reaction because CH2Cl2 or CHCl3 is both reactant and solvent. Its polarity largely acts on the transitional state 1 or 2 and determines the occurance of reaction. Pd(OAc)2 is both reactant and initiator. It affects the reaction by its molecular induction.

Key words: Pd(OAc)2, ERR-ST, Free radical, Chloromethane, Phosphine