Different molecules of liquid crystals such as 4-pentyl-4’-cyanobiphenyl (CB5) and 4-(Hexyloxy)phenyl 4-butylbenzoate, and their interaction with dyes such as 1,2-Diamino-4-nitrobenzene, N,N-Dimethyl-4-nitrosoaniline, and dimethylamino-𝛽-nitrostyrene were investigated by the density functional theory (DFT) using hybrid potential method B3LYP/6-31G. The electronic absorption spectra of isolated dye molecules and the resulting complexes with liquid crystals were calculated. It was shown that the shift of the absorption bands in the spectra of the dye depends on the structure of the complex. The shift and splitting of the bands due to minor impurity of dye molecules placed in the liquid crystal characterizes the mesophase structure.