A method of controlling anchoring energy of surface interaction of liquid crystal photoaligning substances is considered to enhance the liquid crystal display performances. An important parameter of the dye's molecular structure that determines the ratio of polar and azimuthal anchoring energy is the ability to form dimers. The values of dimerization thermodynamic potentials have been found. The probability of the formation of dye molecules dimers is evaluated. The bonds conjugation transfer via intermolecular hydrogen bond is revealed, and anisotropy of polarizability of the hydrogen bond is evaluated. The effect of dimerization on polar and azimuthal anchoring energy of liquid crystal - azo dye system - is shown. A method to control liquid crystals anchoring energy with photoaligning substances is considered to enhance the liquid crystals display performances. Azo dyes with molecules that form dimers via intermolecular hydrogen bond provide higher ratio of polar and azimuthal anchoring energy than dyes whose molecules do not form such dimers. The dimerization thermodynamic potentials and the probability of the formation of the dye molecules' dimers have been estimated. © Copyright 2015 Society for Information Display.