化学学报 ›› 2004, Vol. 62 ›› Issue (24): 2369-2373.    下一篇

研究论文

α-氰基丙烯酸乙酯阴离子聚合的密度泛函理论研究

周亚红1,2, 卑凤利1, 杨绪杰1, 陆路德1, 汪信1   

  1. 1. 南京理工大学化工学院, 南京, 210094;
    2. 江苏警官学院, 南京, 210012
  • 投稿日期:2004-06-09 修回日期:2004-08-18 发布日期:2014-02-17
  • 通讯作者: 汪信,E-mail:njwmq@vip.163.com E-mail:njwmq@vip.163.com
  • 基金资助:
    国家自然科学基金(No.50372028)和国家教育部博士点基金(No.20030288019)资助项目.

Density Functional Theory Study on the Anionic Polymerization of Ethyl α-Cyanoacrylate

ZHOU Ya-Hong1,2, BEI Feng-Li1, YANG Xu-Jie1, LU Lu-De1, WANG Xin1   

  1. 1. Department of Chemistry, Nanjing University of Science & Technology, Nanjing 210094;
    2. Jiangsu Police Officer College, Nanjing 210012
  • Received:2004-06-09 Revised:2004-08-18 Published:2014-02-17

运用密度泛函理论DFT-B3LYP方法,在6-31G*基组水平上,首次全优化计算了α-氰基丙烯酸乙酯与羟基反应势能面上的反应物、过渡态的分子几何、电子结构、能量、IR光谱和热力学性质,求得气相中反应的活化能为13.83 kJ·mol-1,引发速率常数数量级为1010 s-1,从热力学和动力学两方面阐明了阴离子聚合机理.通过自洽反应场(SCRF) B3LYP/6-31G*计算,系统研究了相对介电常数分别为2.02, 2.38, 7.58和12.3的溶剂对反应物和过渡态的结构和反应机理的影响,发现溶剂效应使过渡态的活化能随极性增大而下降,并使引发反应在极性溶剂中接近于无垒反应.

关键词: 密度泛函理论, α-氰基丙烯酸乙酯, 羟基, 溶剂效应

Density functional theory (DFT) at the B3LYP level with 6-31G* basis set was employed to optimize the reactant and the transition state on the potential surface of the ethyl α-cyanoacrylate with water for the first time. The charge, energies, IR spectra and thermodynamic properties were obtained. The activation energy of 13.83 kJ/mol in the gas phase and the order of 1010 s-1 of initiating rate constant were obtained for the reaction. The results both in thermodynamics and kinetics illustrate anionic polymerization mechanism. The impacts of solvent effect on the geometries of reactant and transition state as well as the reaction mechanism were systematically studied for the α-cyanoacrylate with water by self-consistent reaction field (SCRF) technique with different dielectric constants of 2.02, 2.38, 7.58 and 12.3. It was found that the solvent effect would depress the activation energy and finally make the initiation reaction without energy barrier in polar solvents.

Key words: DFT, ethylα-cyanoacrylate, hydroxy, solvent effect