呋喃查尔酮结构与电子光谱的密度泛函理论研究

DFT study on the structures and electronic spectra of furan chalcones

在密度泛函理论的PBE1PBE/6-31G(d)水平上对呋喃查尔酮及其衍生物的几何结构进行优化计算.在获得基态稳定结构的基础上,应用含时密度泛函理论计算其电子吸收光谱,探讨了取代基和溶剂对电子吸收光谱的影响,计算结果与实验结果吻合很好,平均绝对偏差仅为3.3nm(0.04eV).结果表明,取代基的引入和溶剂极性的增大均使光谱发生红移.通过前线轨道分析,揭示了该类化合物的主要吸收峰均源自分子中HOMO→LUMO电子跃迁.

The geometrical structures of furan chalcones have been studied at the PBE1PBE/6-31G（d）level of theory.Subsequently,the electronic absorption spectra have been calculated using the time-dependent density functional theory（TD-DFT）approach.The effects of substitution and solvent on the electronic spectrum have been investigated,which are in good agreement with the experimental results.Comparisons with experimental values lead to a mean absolute error of 3.3 nm（0.04 eV）.The results show that the absorption bands of furan chalcones suffer bathochromic shift with the introduction of substituents and increasing of solvent polarities.In addition,the frontier molecular orbital composition was analysed,which indicates that maximum absorption bands mainly originate from the electronic transitions from the HOMO to the LUMO.