Bowl-Shaped Polyarenes as Concave–Convex Shape Complementary Hosts for C60- and C70-Fullerenes

The X-ray crystal structures of two new co-crystals comprised of C 60 and C 70 fullerenes and a dibenzo[ a, g ]corannulene bowl, namely, (C 28 H 14 )·(C 60 ) and (C 28 H 14 ) 2 ·(C 70 ), are reported. A clear difference is observed between C 60 to C 70, with the latter fullerene molecule being fully ordered and lacking the orientational disorder found in many fullerene co-crystallized products. In the solid state structure of (C 28 H 14 ) 2 ·(C 70 ), two bowl-shaped C 28 H 14 molecules encapsulate the C 70 -cage and exhibit a preferential spatial alignment parallel to the longer axis of the fullerene. In this case, dibenzo[ a, g ]corannulene utilizes only its concave surface for binding, showing a staggered conformation of carbon atoms over the convex surface of C 70 -fullerene. In the solid-state structure of (C 28 H 14 )·(C 60 ), both convex–convex and convex–concave π···π interactions are observed between the curved surfaces of C 28 H 14 and C 60 . The C 60 -core is disordered showing no preferential orientation. In both cases, the formation of π···π adducts was not observed in solutions of chlorinated benzene solvents from which the co-crystals were grown.