香豆素基化合物识别氟离子机制的密度泛函理论

Study on the Mechanism of Fluorine Ion Identification by Coumarin Compounds Based on Density Functional Theory

采用密度泛函理论B3LYP/6-31G(d)方法优化计算以香豆素作为发色基团,胺基为氢键供体形成的化合物(1)及其在氟离子作用下生成的新化合物(2)的分子结构.应用含时密度泛函理论(TD-DFT)计算它们的气相和液相电子光谱,研究了计算方法和溶剂模型对理论光谱的影响.从理论上解释香豆素基化合物可用于识别氟离子的作用机理.在考虑溶剂效应条件下,采用B3LYP/6-31(d)方法优化分子构型后,利用TD-DFT方法获得的电子光谱与实验光谱吻合很好.

The molecular geometries of two compounds were optimized with B3LYP/6-31G（d）method,which based on coumarin,amino compounds for the formation of hydrogen bond donor by 1and the fluoride ions generated under the action of the molecular structure of the new compound 2.The theoretical electronic spectra were calculated with TD-DFT in gas phase and solution phase.Explaining the mechanism of action to identify fluoride based on coumarin in theory.The influences of solvent model and calculation methods on the electronic absorption spectra were also probed.The obtained result suggest that electronic spectra calculated by TD-DFT on the bases of geometries optimized with B3LYP/6-31G（d）are in agreement with experimental ones,and can account for the different spectroscopic properties.