*Paramagnetic Fluorescence Quenching, the allowance of new electronic states upon binding a paramagnetic metal atom
*Photoinduced Electron Transfer (PET), the blocking of a lower energy state due to the binding of a metal atom. 
*Photoinduced Charge Transfer (PCT), the modulation of energy levels in a complex by charge transfer within a conjugated pi system.
*[http://chemwiki.ucdavis.edu/Theoretical_Chemistry/Fundamentals/Fluorescence_Resonance_Energy_Transfer Fluorescence Resonance Energy Transfer (FRET)], the transfer of an exciton from a donor to an acceptor, modulating the emission spectrum.
*Excimer/Exciplex formation, the formation of a state that is a hybrid of the ground and excited states. This has novel fluorescent properties. 
*Chemodosimeters, complexes that undergo irreversible reactions with other species upon binding a metal to form new compounds with novel fluorescent spectra.