Effects of Excimer and Exciplex Formations on Fluorescence Emission
In addition to internal conversion, intersystem crossing, etc, a number of molecular interaction processes such as excited state reactions, complex formation, molecular rearrangements, energy transfer, etc. affect the fluorescence emission of a fluorophore. Several such intermolecular processes compete with the intrinsic de-excitation of the excited fluorophore. Upon excitation, the fluorophore molecules have been observed to participate in reactions that do not occur in the ground state. Excited fluorophores have been observed to make homo- or hetero-dimeric complexes with the ground-state molecules. The excited complexes have emission spectrum very different from that of monomeric fluorophores. These emission properties have been exploited for many applications in chemistry, biology, and many other fields.