Synthesis of a Highly Luminescent Pyrrole-Fused Dicorannulene as a Corrugated π-Extended Carbazole

A pyrrole-fused dicorannulene was designed and synthesized via Pd-catalyzed reactions. This molecule can be regarded as a corrugated π-extended carbazole, which exhibited efficient blue fluorescence (ΦF = 0.56) in contrast to fairly nonemissive pristine corannulene. In addition, deprotonation of the pyrrolic NH by tetrabutylammonium hydroxide gave stable anionic species with a perturbed optical response. Its tetrabutylammonium salt was isolable under ambient conditions, owing to the extensive charge delocalization onto the π-extended chromophore.