ABEEM-σπ方法计算的电荷对烯烃亲电加成反应性的分析  

Investigation on reactivity of markovnikov reactions of alkenes via charge distributions in terms of ABEEM-σπmethod

作　　者：丁艳丽[1] DING Yan-li(College of Science,Shenyang University of Chemical Technology,Shenyang 110142,China)

机构地区：[1]沈阳化工大学理学院,辽宁沈阳110142

出　　处：《分子科学学报》2022年第4期306-311,共6页Journal of Molecular Science

基　　金：沈阳化工大学基金资助项目(LQ2019017);国家自然科学基金资助项目(21403142).

摘　　要：以烯烃亲电加成反应为例,探讨了原子键负性均衡和σπ(ABEEM-σπ)方法计算的电荷分布对反应性的影响,研究再一次证实了烯烃亲电加成反应由起始态烯烃电荷分布决定.研究了电荷分布与活化能、哈米特常量以及静电势等之间的关联,再次体现了ABEEM-σπ方法计算的电荷正确性、合理性及预见性,为ABEEM-σπ方法应用到有机加成、聚合反应奠定了理论基础.The chemical reactions in the double bond of the organic compounds have always been the research object of the chemistry,and widely used in organic,biological,pharmaceutical and other fields.Therefore,it is necessary to accurately deal with the structure of double bond in the model.In view of this,Yang and co-workers proposed and developed the atom-bond electronegativity equalization method plusσπ(ABEEM-σπ)model based on the deasity fumtional theory.One of the significant characteristic of the ABEEM-σπmethod is that the double bond is explicitly considered and partitioned,and a molecule is decomposed into atomic regions,chemical bond regions,i.e.,σandπbond regions,and lone-pair regions.A double bond divided into aσbond region and fourπbond regions,and each atom of the double bond has twoπbond regions.In this paper,electrophilic additions of HCl and HF to a series of asymmetric alkenes in the gas phase have been investigated by ab initio and ABEEM-σπmethod.The effect of the charge distribution calculated by ABEEM-σπmethod on the regioselectivity and reactivity has been discussed.Studies indicate that the difference between activation energies of Markovnikov and anti-Markovnikov addition routes has a linear correlation with differences between charges of Markovnikov and anti-Markovnikov carbon atoms in the initial state of the alkenes.And there is a good linear correlation between differences in electron densities encoded on molecular face and differences in charges of the Markovnikov and anti-Markovnikov carbon atoms in the initial state of the alkenes.Theoretical analysis once again indicates that the regioselectivity and reactivity of the electrophilic addition to alkenes have been determined by the charge distribution of the alkenes in the initial state.To compare our computational charge distribution with Hammett constants σ_(p),the V_(min) of the molecular electrostatic potentials(most negative-valued point in theπ-region of the substituted ethylenes),K_(ED) that is a characteristic mark of t

关 键 词：ABEEM-σπ方法 电荷分布 反应性 烯烃反应 

分 类 号：O641[理学—物理化学]