Properties At The Ground State And Excited State Of 3-(3 '-Pyridyl)-6-Aryl-1-1,2,4-Triazolo[3,4-B]-1,3,4-Thiadiazole Derivatives

The ground states of 3-(3'-pyridyl)-6-aryl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole derivatives (in which, aryl is phenyl (compound A), T-pyridyl (compound B), or styryl (compound C) were optimized with density functional theory at B3LYP level. Ionization potential (I-p), electron affinity (E-A), and other energies of the three compounds were calculated. Absorption spectra were obtained by using Zerner's intermediate neglect of differential overlap (ZINDO) and time-depended density functional theory (TDDFT) methods. Single-excitation configuration interaction (CIS) method was used to calculate the S, excited states of the three compounds and to analyze the relationship between their energies and emission spectra. The absorption and emission spectra were calculated in solvent and compared with the experimental data. The results indicated that the abilities for accepting electrons from A, B to C were strengthened for their electron affinities were increased in turn, and the absorption as well as emission spectra were red-shifted.