香兰素的密度泛函理论研究

Study on characters of vanillin by density functional theory

本文应用密度泛函理论（DFT）的B3LYP方法,在6-31G（d）基组水平上对香兰素进行了研究,计算得到了分子的稳定构型,并对其进行了频率分析,然后利用Gaussview图形软件将频率分析数据转换为红外振动光谱,结果表明,香兰素分子构型属C1点群,分子构型呈现出良好的对称性。对红外振动光谱分析后发现,按照分子振动模式的不同可将光谱划分为4个区域,即0~400、400~1333、1333~1640和1640~4000cm-1。此外,文中对各条谱峰的认定和归属等问题进行了详细讨论,发现红外光谱中振动峰的实际数目远小于简正振动的数目。

Abstract： In this paper, the vanillin is studied at the 6-31G （d） basis set level, using the B3LYP method of density functional theory. Through calculation, the stable structure was gained, and then the frequency analysis was Carried out. At last, frequency analysis data was converted into infrared spectrum by gaussview graphics software. The results showed that structure of vanillin belongs to C1 point Group, and it has favorable symmetry. After the analysis to infrared spectrum, it was found that the infrared spectrum can be divided into four regions, including 0- 400cm-1, 400-1333cm-1, 1333-1640cm-1 and 1640-4000cm-1. Besides, the problem of assignation of spectral lines was discussed in detail, and it is found that the practicable number of the spectral line is less than that of the nor- mal modes.