Flexible fluorophores as the probes for monitoring the structural and dynamical properties of organized molecular media

A description of fluorescence depolarization on flexible fluorophores incorporated into uniaxially organized molecular media is discussed. Fluorophores undergo excited-state irreversible reaction involving intramolecular geometrical transformation. The rates for non-radiative excited-state kinetic relaxation is controlled by the fluorophore-matrix ground- and excited-state aligning interactions and by rotational dynamics of the fluorophores. Rotational dynamics is described in terms of the excited-state potential-restricted diffusion model. Basic properties of the model are discussed and its applicability to different cases important from the experimental point of view is indicated.