高等学校化学学报 ›› 2003, Vol. 24 ›› Issue (12): 2227.

• 论文 • 上一篇    下一篇

SN2反应Xl-+CH3Xr→XlCH3+Xl-(Xl=Xr=F,Cl,Br,I)的价键方法研究

陈衍芬, 宋凌春, 吴玮, 张乾二   

  1. 厦门大学化学系, 理论化学研究中心, 固体表面物理化学国家重点实验室, 厦门 361005
  • 收稿日期:2003-05-06 出版日期:2003-12-24 发布日期:2003-12-24
  • 通讯作者: 吴玮(1962年出生),男,博士,研究员,博士生导师,从事量子化学研究.E-mail:weiwu@xmu.edu.cn E-mail:weiwu@xmu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号:20225311,90206038);教育部重点课题(批准号:02124);高校青年教师奖励基金资助

A Valence Bond Method Study for SN2 Reaction Xl-+CH3Xr→XlCH3+Xl-(Xl=Xr=F,Cl,Br,I)

CHEN Yan-Fen, SONG Ling-Chun, WU Wei, ZHANG Qian-Er   

  1. Department of Chemistry, Center of Theoretical Chemistry, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China
  • Received:2003-05-06 Online:2003-12-24 Published:2003-12-24

摘要: 应用最近发展的价键组态相互作用(VBCI)方法计算了SN2反应Xl-+CH3Xr→XlCH3+X-r(Xl=Xr=F,Cl,Br,I)的反应能垒和价键相关参数.计算结果表明,VBCI能垒与采用分子轨道理论的CCSD(T)方法计算的能垒相一致.讨论了SN2反应的反应参数.

关键词: SN2反应, 从头算, 价键理论, 价键态相关图

Abstract: Barriers and VBquantities for SN2 reaction Xl-+CH3Xr→XlCH3+Xr-(Xl=Xr=F, Cl, Br, I) are calculated by valence bond configuration interaction(VBCI) method. The computational results show that the VB results obtained by using CImethod are in good agreement with those obtained by using the molecular orbital based coupled cluster CCSD method. The reaction parameters for the S N2 identity reaction, including promotion gap G, height of crossing point, resonance energy B, and curvature factor f, are discussed. They show the same trend as that predicted by semiempirical VBtheory, and provide quantitative data for understanding the reaction mechanism.

Key words: SN2 reaction, Ab initio, Valence bond theory, Valence bond state correlation diagram(VBSCD)

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