高等学校化学学报

高等学校化学学报 ›› 1999, Vol. 20 ›› Issue (6): 918.

• 论文 • 上一篇    下一篇

氟、氯和甲基取代丁二酰亚胺的结构、红外光谱和热力学性质的密度泛函理论研究

贡雪东, 肖鹤鸣   

  1. 南京理工大学化学系, 南京 210094
  • 收稿日期:1998-09-14 出版日期:1999-06-24 发布日期:1999-06-24
  • 通讯作者: 肖鹤鸣
  • 作者简介:贡雪东,男,32岁,博士,副研究员.
  • 基金资助:

    国防科工委兵器科技预研基金(批准号:96046)资助课题

Studies on the Structures, Infrared Spectra and Thermodynamic Properties of N-Fluo, N-Chloro and N-Methylsuccinimide by Using Density Functional Method

GONG Xue-Dong, XIAO He-Ming   

  1. Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210094
  • Received:1998-09-14 Online:1999-06-24 Published:1999-06-24

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被引次数

23

摘要： 用密度泛函理论(DFT)的B3LYP方法(6-31G*基组),计算研究了丁二酰亚胺(SIM)的氟、氯和甲基取代物(SIMF,SIMCl和SIMMe)的几何构型、电子结构、红外光谱和热力学性质,讨论了取代基效应.结果表明,SIMF和SIMCl均为平面构型,SIMMe接近平面构型.羰基伸缩振动频率(νC=O)均分裂为两个谱带,低频带出现在1734～1771cm-1,高频带出现在1792～1822cm-1,且前者强于后者.与SIM相比,吸电子基(F和Cl)使νC=O和偶极矩增大,推电子基(CH3)的影响正相反.由校正频率计算了298～800K温度范围的热力学性质熵(S°)和热容(Cp°).

关键词: 密度泛函理论(DFT), 丁二酰亚胺的取代物, 分子几何构型, 红外光谱, 热力学函数

Abstract: Density functional theory(DFT) with the B3LYPmethod and 6-31G*basis set has been employed to investigate the geometries, electronic structures, infrared spectra and thermodynamic properties of N-fluo, N-chloro and N-methylsuccinimide(abbreviated as SIMF, SIMCl and SIMMe, respectively) in gasphase, the effect of substituents on the above properties is discussed. It is shown that SIMF and SIMCl are planar, SIMMe is essentially planar. The C=O stretch vibration(C=O) splits into two bands at 1734-1771 and 1792-1822 cm-1respectively, and the low frequency band has much stronger intensity than the high one. Compared with SIM, electron withdrawing group(F or Cl) makes the C=O and dipole moment larger, while electron contributing group has an opposite effect. The standard thermodynamic functions, i.e., entropy(S°) and heat capacity(Cp°), have been derived with the scaled computed frequencies.

Key words: Density functional theory(DFT), Substituted derivative of succinimide, Molecular geometry, Infrared spectrum, Thermodynamic function

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