香豆素C545T红外光谱的理论计算和实验研究

通过量子化学计算和实验研究了香豆素C545T的红外吸收光谱.采用量子化学密度泛函理论在B3LYP/6-31G(d)基组水平计算了C545T的优化结构参数、红外光谱及其溶剂效应，同时通过傅里叶变换红外光谱仪测量C545T粉末和不同溶剂饱和溶液的红外吸收光谱，计算红外光谱与实验吻合得很好，线性回归相关性系数为0.9996.另外，C545T的红外光谱具有溶剂效应，以C=O为例，其伸缩振动频率随着溶剂极性的增大而减小，即产生红移，实验所测C=O伸缩振动频率与溶剂介电常数线性相关.

Theoretical Calculation and Experimental Study on Infrared Spectra of Coumarin C545T

The infrared absorption spectra of coumarin C545T by quantum chemical calculations and experiments was investigated. Based on quantum chemical density function theory, the optimized structural parameters and the infrared spectra of C545T and the solvent effects of the spectra were calculated at the B3LYP/6-31G (d) level. The infrared absorption spectra of C545T power and its saturated solution with different solvent were also measured by Fourier transform infrared spectrometer. The calculated results are in good agreement with the experiments, with a linear regression correlation coefficient of 0.9996. In addition, the infrared spectrum of C545T exhibits solvent effect. Taking C=O for an example, its vibration frequency decreases with the increase of the solvent polarity, namely bathochromic shift. The experimental vibration frequency of C=O chemical bond is linearly related to the dielectric constant of the solvent.