Study on electronic structures and spectra properties of 3-phenly-6-aryl-1,2,4-triazolo [3,4-b]-1,3,4-thiadiazole with time-dependent density functional theory

Theoretical studies on a series of 3-phenyl-6-aryl-1, 2,4-triazolo [3,4-b] -1 3 4-thiadiazoles were carried out by using the Time-dependent Density Functional Theory(TD-DFT) at B3LYP/6-31G(d) level to obtain the optimized equilibrium structure. The effects of 6-aryl molecular charge transfer, energies of frontier molecular orbitals and the electronic absorption spectra were investigated. On this basis, the electronic transition energy of the excited state was calculated by using time-dependent density functional theory, and lambda(calcd)(max). was obtained. The computed results indicate that the predicted characteristics accord quite well with the available experimental ones and the relative deviation is in the range from 0.071 to 0.041.