A π-extended molecular belt with selective binding capability for fullerene C 70 .

A molecular belt incorporating naphthalene moieties, featuring an ellipsoidal cavity, was precisely engineered through bottom-up synthesis. Its pre-arranged geometry exhibits excellent complementarity to fullerene C 70 , resulting in remarkable selective binding ability ( K = 1.3 × 10 6 M -1 ) for C 70 compared to C 60 ( K = 176 M -1 ), forming a 1 : 1 complex. This superiority was unequivocally demonstrated by the single crystal structure of the complex, which revealed outstanding concave-convex shape complementarity between the two components. This highlights the potential application of molecular belts in the purification and separation of fullerenes.