Photophysical properties of pyrene and its derivatives of biophysical importance

Abstract

With regard to spectral characteristics, pyrene derivatives can be classified in two major groups. The first includes the pyrene-like derivatives (represented by 1-methylpyrene and N-(3-pyrene) maleimide), where the substituent weakly perturbs the symmetry of the π-electron cloud, and which exhibit roughly the spectroscopic properties of pyrene itself. The second includes derivatives like 1-aminopyrene and 1-pyrenecarboxaldehyde which have a fundamentally different spectral behaviour due to the large inductive and mesomeric effect caused by these substituents. The fluorescence of some derivatives containing carbonyl groups is strongly quenched by a mechanism involving radiationless transitions due to the proximity of (π, π*) and (n, π*) states. The information presented is useful for the application of the pyrene derivatives as fluorescent probes.