Complexation of an Anthracene‐Triptycene Nanocage Host with Fullerene Guests through CH⋅⋅⋅π Contacts

A bicyclic anthracene macrocycle containing two triptycene units at the bridgehead positions was synthesized by Ni‐mediated coupling of the corresponding precursor as a cage‐shaped aromatic hydrocarbon host. This cage host formed an inclusion complex with C 60 or C 70 guest in 1 : 1 ratio in solution. The association constants ( K a ) determined by the fluorescence titration method were 1.3×10 4 and 3.3×10 5  L mol  −1 for the C 60 and C 70 complexes, respectively, at 298 K in toluene. DFT calculations revealed that the guest molecules were included in the middle of the cavity with several CH⋅⋅⋅π contacts. The strong affinity of the cage host for the fullerene guests and the high selectivity toward C 70 are discussed on the basis of spectroscopic and structural data.