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  

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

作　　者：邹平[1,2] 李强根[1] 薛英[1] 鄢国森[1] 

机构地区：[1]四川大学化学学院,成都610064 [2]四川农业大学生命科学与理学院,雅安625014

出　　处：《化学学报》2009年第21期2427-2432,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20773089);四川省教育厅青年基金(No.08ZB031)资助项目

摘　　要：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，C1和N02）取代基对活化自由能（△G≠）、键长（△R≠）、键角（△a≠）和自然电荷（△q≠）变化的影响与Harnmet常数（力呈现线性关系△P≠=pσ＋C（P=G，R，a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．The pyrolysis of4-arylideneimino-1,2,4-triazol-3（2H）-one （ATO） and its analogues was investi- gated by the density functional theory method at the B3LYP/6-31 q- q-G（d,p） level of theory. The substituent and temperature effects on the title reaction have been discussed from the aspects of thermodynamic proper- ties, 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, C1, and NO2） in the corresponding activation free energies （△G≠）, bond lengths （△R≠）, bond angles （△a≠）, and atomic charges （Aq≠） have linear correlations with Hammet constant （σ）： △t≠=pσ＋C, （P=G, R, a 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.

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 

分 类 号：O626.26[理学—有机化学]