Triptycene-derived homooxacalixarene analogues: synthesis, structures, and complexation with fullerenes C60 and C70

A series of triptycene-derived homooxacalixarene analogues were conveniently synthesized by a one-pot approach starting from 2,7-dihydroxytriptycene and 1,3-bisbromomethylbenzene derivatives under mild reaction conditions. Similarly, two pairs of "basket-like" triptycene-derived homooxacalixarene analogues were also designed and synthesized. Structures of these macrocyclic molecules in both solution and solid state were studied by NMR experiments and X-ray crystallography. Because of the rigid triptycene units, the homooxacalixarene analogues showed large cavities and fixed conformations even up to 380 K. It was also found that these novel macrocycles could be served as efficient host molecules for complexation with fullerenes C(60) and C(70).