Revisiting the Octadehydro[12]annulenes

Dehydroannulenes are alkyne-rich macrocycles possessing rigid, planar, π-conjugated backbones. Octadehydro[12]annulenes in particular are formally antiaromatic, and have been shown to possess stable reduced states with exploitable LUMO energies. However, very few examples of this type of annulene have been structurally characterized, and there is little information on the stability of these antiaromatic molecules in solution or in the solid state. We have synthesized a range of substituted octadehydro[12]annulenes, and characterized their optical and redox properties. Contrary to prior reports, dehydro[12]annulenes with overlapping π-surfaces are reasonably stable both in solution and thin films, suggesting potential use in practical applications.