对氨基苯磺酸重氮化及偶联反应的热力学计算

Thermodynamic calculations of diazotization and coupling reactions of p-aminobenzene sulfonic acid

基于Gaussian16软件,利用密度泛函理论中的B3LYP和B2PLYP方法,研究了对氨基苯磺酸重氮化、偶联反应中反应物和产物的结构。通过计算,模拟优化了反应物和产物的几何构型与电子分布,得到了反应焓变、吉布斯自由能变及平衡常数。结果表明,重氮化反应的焓变为-117 kJ/mol,吉布斯自由能变为-160 kJ/mol;偶联反应的焓变为-484 kJ/mol,吉布斯自由能变为-460 kJ/mol,由此可知重氮化、偶联反应均为放热、不可逆反应。对氨基苯磺酸重氮化、偶联反应的热力学计算为反应工艺条件的控制和热力学研究提供了理论依据。

Based on Gaussian 16 software,the structures of reactants and products in diazotization and coupling reactions of p-aminobenzene sulfonic acid are studied using the B3LYP and B2PLYP methods in density functional theory.By calculation and simulation,the geometry and electron distribution of the reactants and products are optimized.The results show that the enthalpy change of the diazotization reaction is-117 kJ/mol,and the Gibbs free energy change is-160 kJ/mol.The enthalpy change of the coupling reaction is-484 kJ/mol,and the Gibbs free energy change is-460 kJ/mol,indicating that both diazotization and coupling reactions are exothermic and irreversible.The thermodynamic calculations of diazotization and coupling reactions of p-aminobenzene sulfonic acid provide a theoretical basis for controlling reaction process conditions and thermodynamic research.