Аннотация:Investigation of dynamic and orientation of guest molecules in nematic and smectic liquid crystals by means of EPR spectroscopy showed that admixtures can be localized in the matrix by the several modes. By numerical analysis of EPR spectra the orientation distribution functions of paramagnetic molecules with different structures in macroscopically ordered liquid crystals were determined. In the case of super cooled liquid crystals this procedure is model-free and allows finding order parameters up to 10 rank, that is clarifying thin features of orientation function. It was found that some guest molecules have at least two ways of ordering in the aligned nematic and smectic liquid crystals. It was found also that molecules with different localizations in the matrix possess essentially different dynamic properties. In general it was
concluded that the dominant factor determining localization of the guest molecules in the liquid crystal is not their shape, as it was supposed earlier, but specific interactions with the molecules of the matrix.