ROTATIONAL-DYNAMICS AND CONFORMATIONAL KINETICS IN LIQUID-CRYSTALS

Two particular aspects of solute dynamics in ordered media are analyse d on the basis of the solution of multivariate diffusion equations: th e effects of the solvation dynamics on the rotational motions of dipol ar probes in liquid crystal solvents, and the alteration of reaction p athways in isomerization kinetics caused by the solvent order. The int roduction of a suitable solvent coordinate allows the interpretation o f high frequency contributions in the rotational correlation functions observed by spectroscopic techniques, namely dielectric dispersion, I R and Raman spectroscopy, ESR lineshapes and optical Kerr effect. For molecular systems undergoing conformational changes, a method is offer ed to evaluate the modification of the torsional barriers resulting fr om the anisotropic torques modulated by the molecular shape changes al ong the reaction coordinate.