Concentration quenching and excimer formation by perylene in rigid solutions

The influence of concentration on the fluorescence of perylene dissolved in a rigid polymer matrix has been investigated. As the concentration increases, the monomer fluorescence is quenched and a new emission at lower energies is observed. Diffusional quenching of the type often encountered in fluid solutions cannot occur in this case and the observations are interpreted in terms of excitation transfer by a Forster inductive resonance mechanism, followed by trapping at a site which has a neighbour near enough to form an excited complex.