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研究论文

基于DFT计算的三氟甲氧基苯硝化反应过程分析

张帆a, 郭松a, 杨维成*,a,b,c, 赵基钢*,d, 罗勇b,c   

  1. a上海化工研究院有限公司 上海 200062;
    b聚烯烃催化技术与高性能材料全国重点实验室 上海 200062;
    c上海华谊(集团)公司 上海 200040;
    d华东理工大学 化工学院绿色能源化工国际联合研究中心 上海 200237
  • 收稿日期:2025-12-24 修回日期:2026-01-13
  • 基金资助:
    应急管理部重点科技计划 (No. 2024EMST060601)资助项目.

Analysis of the Nitration Process of Trifluoromethoxybenzene Based on DFT Calculations

Zhang Fana, Guo Songa, Yang Weicheng*,a,b,c, Zhao Jigang*,d, Luo Yongb,c   

  1. aShanghai Research Institute of Chemical Industry Co., Ltd., Shanghai, 200062;
    bState Key Laboratory of Polyolefins and Catalysis Materials, Shanghai, 200062;
    cShanghai Huayi (Group) Company, Shanghai, 200040;
    dInternational Joint Research Center for Green Energy Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237
  • Received:2025-12-24 Revised:2026-01-13
  • Contact: *E-mail: ywcjc@163.com; zjg@ecust.edu.cn
  • Supported by:
    Ministry of Emergency Management Key Science and Technology Program (No. 2024EMST060601).

三氟甲氧基苯(TFMB)的硝基化产物为重要的化工中间体,广泛应用于医药、农药及功能材料的合成领域,其高效制备与反应机理的明晰对相关产业的优化具有重要指导意义。芳香族化合物的硝化反应在本质上是典型的亲电取代反应(EAS),为探究TFMB在混酸体系中的EAS本质,论文采用密度泛函理论(DFT),在M06-2X/6-311+G**理论水平下,对该过程进行了模拟计算与分析。结果表明:TFMB与实际硝化剂NO+ 2之间的电子化学势差为6.28 eV,显示出良好的电子转移能力。平均局部离子化能(ALIE)与静电势(ESP)分析表明,对位为最优亲电进攻位点。热力学计算显示,生成邻、间、对位硝基三氟甲氧基苯的反应焓分别为-97.3、-122.2和-127.6 kJ/mol,吉布斯自由能变均为负值。该反应遵循两步机理,决速步能垒为4.0~7.8 kcal/mol,对位路径能垒最低,邻位次之,间位因能垒高且中间体不稳定而占比最低,与实验结果一致。本研究不仅阐明了 TFMB 硝化反应的微观机理与调控规律,更为同类芳香族化合物的硝化反应设计与优化提供了重要的理论依据。

关键词: TFMB, 硝化反应机理, DFT, EAS, NO₂⁺

The nitration products of trifluoromethoxybenzene (TFMB) are important chemical intermediates, widely used in the synthesis of pharmaceuticals, pesticides, and functional materials. The efficient preparation and clear elucidation of their reaction mechanisms are of significant guiding importance for the optimization of related industries. The nitration of aromatic compounds is essentially a typical electrophilic aromatic substitution (EAS) reaction. To explore the intrinsic nature of the EAS reaction of TFMB in the mixed acid system, this study employed density functional theory (DFT) to perform simulation calculations and analyses on the process at the M06-2X/6-311+G** theoretical level. The results show that the electrochemical potential difference between TFMB and the actual nitrating agent NO₂⁺ is 6.28 eV, indicating a good electron transfer capability. Analyses of average local ionization energy (ALIE) and electrostatic potential (ESP) reveal that the para position is the optimal site for electrophilic attack. Thermodynamic calculations demonstrate that the reaction enthalpies for the formation of ortho-, meta-, and para-nitrotrifluoromethoxybenzene are -97.3, -122.2, and -127.6 kJ/mol, respectively, with all Gibbs free energy changes being negative.The reaction follows a two-step mechanism, with the energy barrier of the rate-determining step ranging from 4.0 to 7.8 kcal/mol. The para reaction pathway exhibits the lowest energy barrier, followed by the ortho pathway, while the meta pathway accounts for the smallest proportion due to its highest energy barrier and the instability of the intermediate, which is consistent with experimental results. This study not only clarifies the microscopic mechanism and regulatory rules of the nitration reaction of TFMB, but also provides an important theoretical basis for the design and optimization of nitration reactions of similar aromatic compounds.

Key words: TFMB, nitration reaction mechanism, DFT, EAS, NO₂⁺