Dianthracenylazatrioxa[8]circulene: Synthesis, Characterization and Application in OLEDs

A soluble, green‐blue fluorescent, π‐extended azatrioxa[8]circulene was synthesized by oxidative condensation of a 3,6‐dihydroxycarbazole and 1,4‐anthraquinone by using benzofuran scaffolding. This is the first circulene to incorporate anthracene within its carbon framework. Solvent‐dependent fluorescence and bright green electroluminescence accompanied by excimer emission are the key optical properties of this material. The presence of sliding π‐stacked columns in the single crystal of dianthracenylazatrioxa[8]circulene is found to cause a very high electron‐hopping rate, thus making this material a promising n‐type organic semiconductor with an electron mobility predicted to be around 2.26 cm2 V−1 s−1. The best organic light‐emitting diode (OLED) device based on the dianthracenylazatrioxa[8]circulene fluorescent emitter has a brightness of around 16 000 Cd m−2 and an external quantum efficiency of 3.3 %. Quantum dot‐based OLEDs were fabricated by using dianthracenylazatrioxa[8]circulene as a host matrix material. Let there be light: A π‐extended, fully conjugated antiaromatic azatrioxa[8]circulene‐polycyclic aromatic hydrocarbon (PAH) structure has been prepared, fully characterized and used in as the emitter in brightly emitting organic light‐emitting diodes (OLEDs), inverted organic light‐emitting diodes (IOLEDs) and quantum light‐emitting diodes (QLEDs).