Self-assembly of organic dyes in supramolecular aggregates

Many scientists probably consider dye aggregation in solution a curse. Here, the adjective "many" should be stressed, as some other researchers thrive on forcing dyes to aggregate in solution. This perspective paper is certainly not meant to be a comprehensive review on the topic. However, for people intrigued by this pervasive phenomenon, I will try to offer a general picture on the self-assembly of dyes into supramolecular aggregates by presenting and discussing key information on their thermodynamics, kinetics, and optical changes. More recent topics will be introduced, such as the impact of external stimuli on dye aggregation, with a particular focus on ion specific effects. Finally, aggregation-induced emission will also be examined.