Pd(OAc)_2与有机膦在氯代烷中的反应机理  

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

作　　者：韦凤萍[1,2] 黄永仁[1,2] 冯良波[1,2] 汪汉卿[1,2] 

机构地区：[1]华东师范大学分析测试中心 [2]中国科学院兰州化学物理研究所

出　　处：《波谱学杂志》1998年第2期131-138,共8页Chinese Journal of Magnetic Resonance

基　　金：国家自然科学基金

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．The new reaction mechanism of Pd(OAc) 2 with dppm or dppe in different chloromethane solvent was studied by EPR-ST method. The used capturer were PBN and POBN. The obtained experimental spectra were simulated. The free radicals \5PPh 2 and containing carbon free radicals were trapped in these experiments. The reaction mechanism was given and discussed. A new ligand PPh 2CHClPPh 2 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 PdCl 2[PPh 2CHClPPh 2]. Some influence factors on the reaction were tentatively discussed. Solvent effects play an important role on the free radical reaction because CH 2Cl 2 or CHCl 3 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.

关 键 词：PD(OAC)2 EPR-ST 自由基 氯代烷 膦 反应机理 

分 类 号：O634.51[理学—高分子化学]