S-Shaped Fused Azacorannulene Dimer:Structural and Redox Properties

Because of their unique structural and chemical properties,buckybowl molecules have attracted considerable attention in a wide range of scientific disciplines.The importance and utility of buckybowl molecules significantly increases once they acquire largerπ-surface area and/or heteroatoms.The fusion of buckybowl molecules has emerged as a new strategy to extend theπ-surface of polycyclic aromatic compounds;however,theπ-extension of heteroatom-embedded buckybowls by the fusion strategy is still rare.Here we report the synthesis and propeties of a fused azacorannulene dimer bearing a C62N2 core(1a),which can also be regarded as a double aza[5]helicene.Due to the steric repulsion between two azapentabenzocorannulene moieties,this molecule shows a rigid S-shaped structure where the two azacorannulene bowls face in opposite directions.Stepwise chemical oxidation of 1a resulted in the formation of the corresponding radical cation(1a^(+))and dication(1a^(2+)),providing an important insight into their aromaticity.The fusion of heteroatom-embedded buckybowls provides a powerful way to synthesizeπ-extended polycyclic aromatic molecules.