物理化学学报 >> 2018, Vol. 34 >> Issue (5): 519-527.doi: 10.3866/PKU.WHXB201710126

所属专题: 密度泛函理论中的化学概念特刊

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Fukui函数和局域软度应用于亲电加成反应的区位选择性的研究

朱尊伟1,杨巧凤1,徐珍珍1,2,*(),赵东霞1,*(),樊红军2,杨忠志1   

  1. 1 辽宁师范大学化学化工学院,辽宁大连116029
    2 中国科学院大连化学物理研究所,辽宁大连116029
  • 收稿日期:2017-08-30 发布日期:2018-01-24
  • 通讯作者: 徐珍珍,赵东霞 E-mail:jane_xu@dicp.ac.cn;zhaodxchem@lnnu.edu.cn
  • 基金资助:
    国家自然科学基金(21483083);国家自然科学基金(21483083, 21133005);辽宁省自然科学基金(2014020150)

Fukui Function and Local Softness Related to the Regioselectivity of Electrophilic Addition Reactions

Zunwei ZHU1,Qiaofeng YANG1,Zhenzhen XU1,2,*(),Dongxia ZHAO1,*(),Hongjun FAN2,Zhongzhi YANG1   

  1. 1 School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, Liaoning Province, P. R. China
    2 Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning Province, P. R. China
  • Received:2017-08-30 Published:2018-01-24
  • Contact: Zhenzhen XU,Dongxia ZHAO E-mail:jane_xu@dicp.ac.cn;zhaodxchem@lnnu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21483083);the National Natural Science Foundation of China(21483083, 21133005);the Natural Science Foundation of Liaoning Province, China(2014020150)

摘要:

Fukui函数、局域软度、广义Fukui函数以及广义软度通常被称为反应描述符。使用它们研究和探讨了HCl与不对称烯烃以及溴苯硒与不对称苯乙烯的亲电加成反应的区位选择性。在MP2/6-311++G(d, p)理论水平下,采用有限差分方法计算这些反应描述符,同时也使用ABEEMσπ方法进行了计算。ABEEMσπ模型下的局域软度和广义局域软度,分别结合局域硬-软酸碱(HSAB)原理,得出亲电试剂氯化氢与溴苯硒,更容易进攻不对称乙烯和苯乙烯中的马氏碳原子,符合马氏规则。而有限差分方法不能完全地解释该系列反应的区位选择性。此外,主要产物所对应的马氏碳原子的广义局域软度值,就能够预测出此类反应的活性序列,所得结果与速率常数有很好的关联。

关键词: Fukui函数, 局域软度, 局域硬-软酸碱原理, 亲点加成反应, 有限差分近似;ABEEMσπ模型

Abstract:

Regioselectivities of electrophilic addition reactions of hydrogen chloride to asymmetric alkenes and benzeneselenenyl bromide to substituted styrenes have been investigated by using reactivity descriptors, including Fukui function f(r), local softness s(r), generalized Fukui function fG(r), and generalized local softness sG(r). All of them are obtained from the finite difference approximation method calculated by ab initio method at MP2/6-311++G(d, p) level of theory and our ABEEMσπ model, respectively. According to the generalized version of the local hard-soft and acid-base (HSAB) principle, the forecasted regioselectivities of our investigated additions using the ABEEMσπ model are in fair agreement with the experimental values. In particular, we can also rationalize their reaction rate constants by the generalized local softness, i.e., the softest the site is, the easiest the reaction is. Hence, the generalized reactivity descriptors work quite well.

Key words: Fukui function, Local softness, Local hard-soft and acids-bases (HSAB) principle, Electrophilic addition reactions, Finite difference approximation, ABEEMσπ model

MSC2000: 

  • O641