Kuznyetsova A. Spectroscopic manifestation of structural ordering of wall-adjacent layers of organic polar fluids.

The dissertation is devoted to examination of the mechanism of dimerisation and structural orderliness thin wall adjacent layers of organic liquids with the anisotropic molecules. Such liquids occupy the intermediate standing between isotropic liquids, which are not capable to form liquid-crystalline structure, and NLC for which formation it is not required presence of a solid substrate. In the dissertation the theoretical model in which the dipole-dipole and a dispersive interaction between particles of a liquid is considered, and also orientational interaction between particles of a liquid and a lyophilic solid substrate is featured. The expressions featuring dependence of monomers and dimers order parameters, and also monomer's concen tration vs the distance up to a solid substrate are gained. Within the limits of the offered model existence of biphase system is predicted: one of them, immediately adjoining to a surface of a solid substrate, is orientationally ordered and consists mainly of dimers,and another one represents the isotropic liquid phase in which monomers predominate. These phases are sepa-rated from each other by a sharp demarcation. At transition of this boundary monomers and dimers order parameters sharply decrease up to zero, and monomer's concentration increases up to 1. The offered model has gained the experimental confirmation at examination of depen dence of the shape of electronic-vibration and infrared spectra of nitrobenzene and metoxybenzene vs layer thickness. In series of these spectra isobestical points were found out. On the basis of what it has been made the inference about the existence of the two types of the absorp tion centres, one of which crresponds to monomers, and another - to dimers. On the basis оf examination of the shape of electronic-vibration spectra of nitrobenzene and metoxybenzene it was shown, that the basic role in formation OOWL orientational interaction between monomers and dimers with a solid substrate is played.