Catching Fullerenes: Synthesis of Molecular Nanogloves

Herein, we report the synthesis of a new series of rigid, all meta-phenylene, conjugated deep-cavity molecules, displaying high binding affinity towards buckyballs. A facile synthetic approach with an overall combined yield of approximately 53% in the last two steps has been developed using a templating strategy that combines the general structure of resorcin[4]arene and [12]cyclo-meta-phenylene. These two moieties are covalently linked via four acetal bonds, resulting in a glove-like architecture. ¹H NMR titration experiments reveal fullerene binding affinities (K_a) exceeding ≥10⁶ M^-1. The size complementarity between fullerenes and these scaffolds maximizes CH⋯π and π⋯π interactions, and their host:guest adduct resembles a ball in a glove, hence their name as nanogloves. Fullerene recognition is tested by suspending carbon soot in a solution of nanoglove in 1,1,2,2-tetrachloroethane, where more than a dozen fullerenes are observed, ranging from C₆₀ to C₉₆.