Strongly emitting fluorophores based on 1-azaperylene scaffold.

A novel blue-emitting polycyclic aromatic system was synthesized via anion-radical coupling. Its efficient direct hydroxylation led to a phenol possessing an intramolecular hydrogen-bond system. Since the energy gap difference between the enol and keto forms of this molecule is very small, characteristic of ESIPT chromophores, bathochromically shifted fluorescence was not observed.