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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (21): 2427-2432. 上一篇    下一篇

研究论文

密度泛函理论研究温度和取代基对4-亚芳基亚氨基-1,2,4-三唑-3(2H)-酮气相热分解的影响

邹平a,b   李强根a    薛英*,a    鄢国森a   

  1. (a四川大学化学学院 成都 610064) (b四川农业大学生命科学与理学院 雅安 625014)
  • 投稿日期:2008-12-15 修回日期:2009-05-15 发布日期:2009-07-24
  • 通讯作者: 薛英 E-mail:xueyingscu@163.com, xueying@mail.sc.cninfo.net

Effects of Substituent and Temperature on the Gas-phase Pyrolysis of 4-Arylideneimino-1,2,4-triazol-3(2H)-ones: a DFT Investigation

Zou, Ping a,b    Li, Qianggena     Xue, Ying*,a    Yan, Guosena   

  1. (a College of Chemistry, Sichuan University, Chengdu 610064) (b College of Life Science, Sichuan Agriculture University, Ya'an 625014)
  • Received:2008-12-15 Revised:2009-05-15 Published:2009-07-24

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采用密度泛函理论(DFT)方法, 在B3LYP/6-31＋＋G(d,p)水平上研究了4-亚芳基亚氨基-1,2,4-三唑-3(2H)-酮及其类似物的气相热分解反应. 从热力学性质、几何结构参数、自然电荷分布、温度效应等角度探讨不同取代基对标题物热分解反应的影响. 结果表明: R (R＝H, CH2CH2CN)取代基对反应影响很小; 而苯环上Y (Y＝MeO, Me, H, Cl和NO2)取代基对活化自由能(ΔG≠)、键长(ΔR≠)、键角(Δα≠)和自然电荷(Δq≠)变化的影响与Hammet常数(σ)呈现线性关系ΔP≠＝ρσ＋C (P＝G, R, α和q, r＞0.95). 给电子基团使得相应的活化自由能降低, 键长变短, 键角变大, 自然电荷增加; 吸电子反之.

关键词: 4-亚芳基亚氨基-1,2,4-三唑-3(2H)-酮, 热分解, 密度泛函理论, 取代基效应

The pyrolysis of 4-arylideneimino-1,2,4-triazol-3(2H)-one (ATO) and its analogues was investigated by the density functional theory method at the B3LYP/6-31＋＋G(d,p) level of theory. The substituent and temperature effects on the title reaction have been discussed from the aspects of thermodynamic properties, geometric parameters, and natural population analysis. The calculated results show that the substituent R has little effect on the reaction, while the changes caused by the substituents Y on the benzene ring (Y＝MeO, Me, H, Cl, and NO2) in the corresponding activation free energies (ΔG≠), bond lengths (ΔR≠), bond angles (Δα≠), and atomic charges (Δq≠) have linear correlations with Hammet constant (σ): ΔP≠＝ρσ＋C, (P＝G, R, α and q, r＞0.95). The electron-donating group decreases the activation free energies and bond lengths, but increases the bond angles and natural electric charges. By contraries, the electron-withdrawing group has the opposite effect.

Key words: 4-arylideneimino-1,2,4-triazol-3(2H)-ones, pyrolysis, the density functional theory, substituent effectfunctional theory, substituent effect