苯甲酸分子表面增强拉曼光谱的密度泛函理论研究

Study of Density Functional Theory for Surface-Enhanced Raman Spectra of Benzoic Acid

基于密度泛函理论,利用量子化学软件,在B3LYP/6-311G**(C,H,S)/Lanl2dz(Ag)水平上对苯甲酸(Benzoic Acid,C7H6O2,BA)进行几何优化,得到BA与Ag原子和Ag离子结合,即C7H5O2-Ag和C7H5O2Ag的平衡构型,在此基础上得到了两种形态的计算拉曼谱图,并和其他文献值进行比较,其中C7H5O2Ag的计算结果与文献中的BA表面增强拉曼光谱的实验值符合得较好。同时采用简正振动分析方法得到其势能分布,从而对其简正振动模式进行了全面归属。

In the present paper, DFT method at the B3LYP/6-311G（C, H, S）/Lanl2dz （Ag） level was used to optimize molecular configurations of benzoic acid （BA）. The opti- mized geometries and calculated Raman spectra of the complexes C7H5O2Ag and C7H5O2Ag were obtained. The calculated Raman spectrum of C7H5O2Ag is in good agree- ment with the surface-enhanced Raman spectrum experimental results of other literatures values. The potential energy distribution of BA adsorbed on Ag was calculated on the ba- sis of the optimized structure and vibrational analysis. We made the assignments of all the fundamentals.