journal6 ›› 2010, Vol. 31 ›› Issue (3): 86-89.

• 化学化工 • 上一篇    下一篇

乙烯氧基在苯乙烯醚亲电取代反应中的定位效应

  

  1. (衡阳师范学院化学与材料科学系,湖南 衡阳 421008)
  • 出版日期:2010-05-25 发布日期:2012-04-17
  • 作者简介:邝代治(1955-),男,湖南临武人,衡阳师范学院化学与材料科学系教授,主要从事金属有机化学研究.
  • 基金资助:

    湖南省高校教改研究资助项目(湘教通[2008]263号148);湖南省重点建设学科和有机化学教学团队资助项目

Orientation Effect of Ethyleneoxy on  Electrophilic Substitution  Reaction of Ethenyl Phenyl Ether

  1.  (Department of Chemistry and Materials Science,Hengyang Normal University,Hengyang  421008,Hunan China)
  • Online:2010-05-25 Published:2012-04-17

摘要:从理论上研究了苯乙烯醚的电子结构,结果表明,苯乙烯醚的乙烯氧基在空间的位置影响苯乙烯醚的原子电荷分布和能量,从而影响苯乙烯醚的亲电取代反应.苯乙烯醚的O—Ph键旋转,形成不同构象之间的最大与最小体系能量值之差ΔE仅0.005 402 a.u..当O12—C1C13与苯环垂直时,体系能量最低,为稳定的优势构象.苯乙烯醚中乙烯氧基表现为吸电基,它的作用使邻位碳原子的负电荷比苯环碳原子多,邻位亲电取代反应中间体最稳定,反应的途径最有利,乙烯氧基主要表现为邻、对位定位基.

关键词: 苯乙烯醚, 电子结构, 乙烯氧基, 定位效应

Abstract: The electronic structure of ethenyl phenyl ether(ethenyloxy benzene) and the orientation effect of the ethenyloxy on electrophilic aromatic substitution are studied.The results show that the energy and atomic charge of ethenyl phenyl ether  are influenced by the space location of the ethenyloxy,and so is the orientation effect of the ethenyloxy on the reaction of electrophilic aromatic substitution. The molecular conformation is formed by the O—Ph bond rotation,the difference between the maximal and minimal protential energy of conformations ΔE is only 0.005 402 a.u..The potential energy of the molecule is at a minimum when  O12—C1C13 is vertical to  benzene ring.The ethenyloxy is an electron-withdrawing group,but there is more negative charge of ortho-carbon atom  than that  of benzene carbon.The ortho electrophilic substitution reaction intermediate is the most stable. The products of ortho-substituted by the carbocation dehydrogenation shown to the ethenyloxy is ortho- and para- directing group.

Key words: ethenyl phenyl ether, electronic structure, ethyleneoxy, orientation effect

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