A π-extended molecular belt with selective binding capability for fullerene C70†

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 C₇₀, resulting in remarkable selective binding ability (K = 1.3 × 10⁶ M⁻¹) for C₇₀ compared to C₆₀ (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.