Halogen bonding in the design of organic phosphors

Halogen bonding as a new strategy for introducing heavy atom perturbers in defined stoichiometry in the design of organic phosphors is reviewed. Considering ten novel cocrystals assembled by polyaromatic hydrocarbons (PAHs) and their heterocyclic analogues and haloperfluorobenzenes using the new strategy, apart from biphenyl cocrystals they all phosphoresce strongly, showing that the new methodology can induce phosphorescence by a heavy atom effect. More interesting, the phosphorescence properties, including excitation/emission wavelengths and decay dynamics, show dependence on the structure of the PAHs and interaction patterns, which is very important and valuable in modulation of the expected colors of luminescent materials.