ABSTRACT We report the cyclodehydrogenation of octaphenyl cyclooctatetraene on molten alkali metal, proceeding through six sequential cyclization steps to form a bay‐fused dimer of dibenzoperylene, DBP . This molecule represents a well‐defined junction between armchair edges of graphene subunits with controlled electronic coupling. The pronounced steric congestion at the molecular core generates a rigid structure composed of two orthogonally fused nanographene sheets—a structure that we designate as DBP2 . Despite orthogonality, the nanographene moieties in DBP2 exhibit strong electronic coupling. Spectroscopic and electrochemical measurements demonstrate electronic delocalization and robust inter‐subunit coupling. The canonically disallowed communication across an eight membered ring gives rise to a pronounced chiroptical response ((| g abs | ≈ 0.01 and | g lum | ≈ 0.01) in the persistently chiral enantiomers of DBP2 . DBP2 is an efficient two‐electron acceptor and shows pronounced absorption throughout the visible spectrum. More broadly, the novel cyclodehydrogenation reaction on molten alkali metals provides access to a broader class of contorted nanographenes for optoelectronics, energy storage, and chiroptical applications.
Lackovic et al. (Mon,) studied this question.