茜素与AcO~-阴离子的超分子作用及紫外-可见吸收光谱的理论研究

采用密度泛函方法(DFT/B3LYP),在6-31+G水平上分别优化茜素以及AcO-阴离子复合物的几何构型.从几何结构参数、电荷布居和前线轨道能量等方面探讨了复合物形成过程中主体分子的构象变化,以及主客体间的超分子作用.用含时密度泛函方法(TD-B3LYP/6-31+G)分别计算了主体分子以及与阴离子形成复合物的紫外-可见吸收光谱.根据所得复合物的特征吸收峰波长红移情况,从理论上较好地解释了主体分子通过氢键与AcO-形成稳定阴离子复合物的实验事实.结果表明,乙腈溶剂中茜素对AcO-具有较强的超分子作用和选择性识别能力.

A DFT study on supra-molecular interaction between alizarin and AcO- anion

For alizarin and its AcO- complexes,their geometry configurations were optimized by using the DFT/B3LYP/6-31+G method.The conformation changes of the host and the supra-molecular interactions between the host and anion the complexes,have been investigated from the geometry configuration parameters,the Mulliken charge analysis and the frontier orbital energies.Then,the UV-Vis spectrum data of the host and its anion complexes were obtained by TD-B3LYP/6-31+G method.On the basis of the shift of the wavelength at the typical absorbance peaks,we explained the experimental findings that alizarin and AcO- host-guest complexes were formed throudh hydrogen bonds.It was concluded that alizarin is of the supra-molecular interaction with AcO-and capable of the strong anion recognition in acetonitrile.