Theoretical studies on stilbazoles have been carried out using density functional theory (DFT) at B3LYP/6-31G*, 6-31G**, 6-31＋G* level to obtain optimized equilibrium structure. The calculation results indicate that the compounds have C₁ structure. The carbon and the oxygens in the ester group come into formation of different large π bonds with the benzene ring and there is a dihedral angle between 60° and 62° because of place blocking and conjugate effects. On this basis, the first vertical excited state electronic transition energy was calculated by time-dependent density function theory (TD-DFT), and λ_max was obtained. The computed results show that the length of alkyl chain in the end of stilbazoles has no effect on the structure and electronic spectra.

Key words: liquid crystal, density functional theory, structure, spectrum, stilbazole