What is "circulene"

n. (context organic chemistry English) Any polycyclic aromatic hydrocarbon consisting of a closed ring of fused benzene rings

A circulene is a macrocyclic arene in which a central n-sided polygon is completely surrounded and fused by benzenoids. [5]circulene ( corannulene), [6]circulene ( coronene), [7]circulene, and [12]circulene ( kekulene) have all been synthesized in the laboratory. These compounds belong to a larger class of geodesic polyarenes. Whereas [5]circulene is bowl-shaped and [6]circulene is planar, [7]circulene has a unique saddle-shaped structure (compare to cones and partial cones in calixarenes). Conceptually related compounds are the helicenes.