Benzo[a]acecorannulene: surprising formation of a new bowl-shaped aromatic hydrocarbon from an attempted synthesis of 1,2-diazadibenzo[d,m]corannulene.

[Structure: see text] Flash vacuum pyrolysis of 7,10-bis(2-bromophenyl)acenaphtho[1,2-d]pyridazine (C26H14Br2N2) has resulted in a surprising transformation, including dinitrogen loss, to give benzo[a]acecorannulene, a novel C26H12 bowl-shaped fullerene fragment.