1-(2,6-二氯-4-三氟甲基苯基)-3-氰基-5-氨基吡唑的结构、光谱与热力学性质

Structure,Spectra and Thermodynamic Properties of 1-(2,6-Dichloro-4-trifluoromethylphenyl)-3-cyano-5-amino-pyrazole

在B3LYP/6-31++G**水平对1-(2,6-二氯-4-三氟甲基苯基)-3-氰基-5-氨基吡唑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,该分子的苯基环和吡唑环不在同一个平面上,两个平面的二面角在84°左右.最低能量吸收谱线的波长为339 nm,对应HOMO→LUMO的π→π*和n→π*电子跃迁.热力学计算显示该分子的气态热力学函数熵Sm和焓Hm与温度有较好的线性关系,Sm=421.710 5+0.687 3T(J.mol-1.K-1)和Hm=306.673 1+0.426 7T(kJ.mol-1).

The structure optimization and frequency calculation have been carried out at B3LYP/6-31 ＋ ＋ G ＊ ＊ level, and IR spectrum, Raman spectrum and thermodynamic properties at different temperatures have been obtained. The results indicate that the phenyl ring and pyrazole ring are in different planes, and there is a dihedral angle of about 84°. The wave length of the lowest-energy absorption spectra is found to be 339 nm with the electronic transition from HOMO to LUMO （π→π＊ and n→π＊ ）. Thermodynamic calculations show that the entropy Sm and enthalpy Hm have a good linear relationship with the temperature T, Sm = 421. 710 5 ＋ 0. 687 3T（J· mol^-1· K^-1） and Hm =306.673 1 ＋0.426 7T（kJ · mol^-1）.