A Macrocycle Based on a Heptagon‐Containing Hexa‐peri‐hexabenzocoronene

Abstract

A cyclophane incorporating two units of a heptagoncontaining extended polycyclic aromatic hydrocarbon (PAH), analogue of the hexa-peri-hexabenzocoronene (HBC) moiety (hept- HBC), is reported. This cyclophane represents a new class of macrocyclic structures that incorporate for the first time sevenmembered rings within extended PAH frameworks. The saddle curvature of the hept-HBC macrocycle units induced by the presence of the non-hexagonal ring along with the flexible alkyl linkers generate a cavity with shape complementarity and appropriate size to enable  interactions with fullerenes. Therefore, the cyclophane forms host-guest complexes with C60 and C70 with estimated binding constants of Ka = 420 ± 2 M-1 and Ka = (6.49 ±0.23) × 103M-1 respectively. As a result, the macrocycle can selectively bind C70 in the presence of an excess of a mixture of C60 and C70.