2-EXCITED-STATE REVERSIBLE-REACTIONS AND FLUORESCENCE DEPOLARIZATION IN UNIAXIALLY ORGANIZED MOLECULAR MEDIA

The problem of fluorescence depolarization in uniaxially organized mol ecular media in the case of the fluorophores undergoing reversible exc ited-state reactions, is discussed. The two-ground- and two-excited-st ate species case is considered under the assumptions that the species- associated ground- and excited-state solute-matrix aligning interactio ns and the species-associated diffusion tensors are different. The sta te-to-state kinetic relaxation process is described in terms of rate c onstants which are independent of the angular orientations of the fluo rophores within the aligned medium. Basic properties of the model are illustrated and discussed. (C) 1998 Elsevier Science B.V. All rights r eserved.