Bisazapentalene Dication: Global Aromaticity and Open-Shell Singlet Ground State

Antiaromatic moieties fused in polycyclic pi-conjugated molecules usually exhibit strong localized antiaromaticiy. Herein, we reported the synthesis and properties of a bisazapentalene dication (BAP2+) obtained from in situ two-electron oxidation of neutral species 8. Noteworthily, it possesses global aromaticity and an open-shell singlet ground state. This study underlines the importance of heteroatoms in determining the delocalization of pi-electrons and the aromaticity of molecules in their oxidized states.