Two-Heptagon Saddle-Shaped Nanographene as a Host for Fullerene Assembly

A two-heptagon saddle-shaped nanographene was synthesized through a palladium-catalyzed 4+3 decarboxylative annulation as a key step. This negatively curved π-system binds C 60 and C 70 with moderate affinities with distinct supramolecular architectures. C 60 of the (C 60 ) 2 ⊂ 1 complex assembles into perpendicular zigzag arrays with short interfullerene contacts, whereas C 70 of the C 70 ⊂ 1 complex adopts a unidirectional zigzag arrangement. These findings demonstrate that negative curvature and substituent placement influence supramolecular packing, offering design principles for fullerene–nanographene assemblies.