【摘要】 在密度泛函理论(DFT)的B3LYP/6—31G*水平上对一系列靛族染料化合物的几何构型进行优化计算:在获得基态稳定结构的基础上,应用含时密度泛函理论(TD—DFT)在相同水平下计算其电子吸收光谱。探讨了不同给电子基团和发色体系的延伸对电子吸收光谱的影响,得到了与实验基本一致的变化规律。结果表明,给电子能力的增强和发色体系的纵向延伸均使光谱产生一定红移。通过对前线轨道组成进行自然布居分析,揭示了靛族染料的发光均源自分子中HOMO—LUMO(π→π*)电子跃迁。更多还原

【Abstract】 The geometrical configurations of indigoid dyes were studied at the B3LYP/6-31G* level of density functional theory (DFT). Subsequently, the electronic absorption spectrum was calculated using the time-dependent density functional theory (TD-DFT) approach at the same level. The effects of the electron-donating groups and various chromophoric systems on the electronic absorption spectrum were investigated, good results were achieved as compared with the experimental results. The results showed that the absorption band of indigoids suffered a bathochromic shift as the electron-donating effect enforced and conjugation of the molecules extended. In addition, the frontier molecular orbital composition was analyzed by natural population analysis (NPA), which revealed that the emission was originated from the electronic HOMO-LUMO( π→π *) transitions.更多还原