Interpretation of transient Stokes shift experiments in liquid crystals.

We have extensively investigated the effect of the nematic barrier on the transient Stokes shift dynamics of a fluorescent dye with the aid of a stochastic model. A theoretical transient Stokes shift correlation function has been defined and its characteristic decay time has been determined for a wide range of dynamical regimes and dipolar coupling of the solute with the polar environment. Recent experimental data have been reviewed and discussed in relation with the newly available theoretical results.