2-（甲苯-4-磺酰胺基）-苯甲酸的结构、光谱与热力学性质的理论研究

在B3LYP/6-31++G^**水平对2-（甲苯-4-磺酰胺基）-苯甲酸分子进行几何构型优化和频率的计算，得到红外光谱，拉曼光谱和不同温度下的热力学性质.结果显示，该分子羧基的碳氧原子、磺酰胺基的氮原子与苯环形成不同的离域大π键，空间位阻效应和共轭效应使两个苯环不在同一平面，二面角为63.2°.使用含时密度泛函理论方法计算第一激发态的电子垂直跃迁能，得到最大吸收波长为312.7?nm，属于近紫外区，这与该分子在二氯甲烷溶剂中的实验测得值307?nm一致.关键词：2-（甲苯-4-磺酰胺基）-苯甲酸光谱热力学性质密度泛函理论

Theoretical study on the structure,spectra and thermodynamic property of 2-(toluene-4-sulfonylamino)-benzoic

The structure optimization and frequency calculation have been carried out at B3LYP/6-31++G^** theoretical level，and IR spectrum，Raman spectrum and thermodynamic property at different temperatures have been obtained. The results indicate that the carbon and the oxygen in the —COOH group，and the nitron in —（OS）₂—NH group come into formation of different large π bonds with the benzene rings，and there is a dihedral angle of 63.2° because of place blocking and conjugate effect. The first vertical excited state electronic transition energy was calculated by time-dependent density functional theory，and the maximal absorption wavelength was obtained at 312.7?nm，belonging to near UV，which is in good agreement with experimental value of 307?nm in dichloromethane solvent.
Keywords：2-（toluene-4-sulfonylamino）-benzoic acidspectrathermodynamic propertiesdensity functional theory