As an organic molecule catalyst, N,N′,N″-trihydroxyisocyanuric acid can selectively catalyze the oxidation of the methyl group of waste 2,4,6-trinitrotoluene to generate 2,4,6-trinitrobenzoic acid. This reaction can avoid environmental pollution by inorganic heavy metal catalysts. In this study, four reaction stages of this catalytic reaction were designed and validated computationally at the M06-2X-D3ZERO/6-311G(d,p) level using the acetic acid solvent model. These validations include transition state searches, intrinsic reaction coordinate calculations, reactant and product optimizations, and frequency calculations. The final reaction network of 23 transition states shows that after N,N′,N″-trihydroxyisocyanuric acid activation and common reaction, the network bifurcates into two stages: alcohol to carboxylic acid and aldehyde to carboxylic acid. Although the former stage releases about 155 kcal/mol of Gibbs free energy, less than the 177 kcal/mol from the latter stage, the overall reaction equation shows that the pathway including former stage does not consume the catalytically active substance IM_T2, which saves the energy required for reactivation and is thus more favorable. Furthermore, the key transition states in the reaction network include bimolecular substitution reactions and proton-hopping transfer reactions. Analyses of their interaction region indicators and intrinsic reaction coordinate results demonstrate strong selectivity. Additionally, the energy barriers and heat releases of the latter are twice and 1.3 times greater than those of the former, respectively. In summary, this study elucidated two competitive reaction pathways and identified the more energetically favorable and selective pathway, and it provides useful insights for further optimization of industrial utilization of 2,4,6-trinitrotoluene.

中文翻译：

---

2,4,6-三硝基甲苯资源化利用反应机理研究一：N,N′,N″-三羟基异氰脲酸催化剂在乙酸中生成2,4,6-三硝基苯甲酸

N , N ', N ''-三羟基异氰脲酸作为有机分子催化剂，可以选择性催化废2,4,6-三硝基甲苯的甲基氧化生成2,4,6-三硝基苯甲酸。该反应可以避免无机重金属催化剂对环境的污染。在本研究中，使用乙酸溶剂模型在 M06-2X-D3ZERO/6-311G(d,p) 水平上设计并验证了该催化反应的四个反应阶段。这些验证包括过渡态搜索、固有反应坐标计算、反应物和产物优化以及频率计算。最终的23个过渡态的反应网络表明，N , N ', N ''-三羟基异氰脲酸活化并共同反应后，网络分为两个阶段：醇到羧酸和醛到羧酸。虽然前级释放了约155 kcal/mol的吉布斯自由能，低于后级的177 kcal/mol，但总体反应方程表明，包括前级的路径不消耗催化活性物质IM_T2，从而节省了重新激活所需的能量，因此更有利。此外，反应网络中的关键过渡态包括双分子取代反应和质子跳跃转移反应。对它们的相互作用区域指标和内在反应坐标结果的分析显示出很强的选择性。此外，后者的能量势垒和热量释放分别是前者的两倍和1.3倍。综上所述，本研究阐明了两条竞争反应途径，并确定了能量上更有利、选择性更强的途径，为进一步优化2,4,6-三硝基甲苯的工业利用提供了有益的见解。