两种薁磺酰胺席夫碱衍生物分子的光谱和热力学性质计算研究

Computational study of molecular spectra and thermodynamic properties of two kinds of azulene sulfonamide schiff base derivatives

使用密度泛函理论B3LYP方法,对两种薁磺酰胺席夫碱衍生物的分子结构、红外光谱、电子吸收光谱及热力学性质进行计算研究,并基于Tomasi的极化统一场模型(PCM)讨论电子吸收光谱的溶剂效应.结果表明,红外光谱计算值与实验值吻合,电子吸收光谱都是π-π*跃迁,溶剂及溶剂极性大小对最低能量吸收波长无影响.酚羟基的引入增大席夫碱的共轭体系,有利于提高分子的生物活性.298 K时,两种衍生物的ΔfHθm分别为5544.3,5304.6 k J·mol-1,ΔfGθm分别为20548.7,20331.2 k J·mol-1,Sθm分别为857.5,881.1 J·mol-1·K-1.

The molecular structures , IR spectra, electronic absorption spectra and thermodynamic properties of two kinds of azulene sulfonamide Schiff base derivatives were calculated by using the density functional theory B3LYP method.The polarized continuum models （ PCM） of Tomasi were used to discuss the solvent effects .The computational results showed that the IR spectrum values are in accord with the experimental results , the absorp-tion spectra could be assigned to a charge transfer （ CT） state with a π-π＊character;The using solvents and the polarity of solvents have no effect on the maximum absorption wavelength .The phenolic hydroxyl leads to the larger πconjugated system of Schiff base moiety , which has an important role to improve the molecular biological activity.The gaseous thermodynamic properties of compounds Δf Hθm are 5544.3 , 5304.6 kJ·mol^-1 , Δf Gθm are 20548.7, 20331.2 kJ· mo^l-1 , Sθm are 857.5 and 881.1 J· mol^ -1· K^-1 , respectively.