Efficient Synthesis of Arylhydrazone Capsule with Single Precursor for Encapsulation of C60 and C70

Abstract

Molecular cages are distinguished supramolecular structures with stable cavities, enabling applications in molecular recognition, catalysis, and drug delivery. While the synthesis of purely organic cages is less common and often hindered by entropy-related challenges in irreversible reactions. In this study, we present a novel single-precursor strategy featuring dual aldehyde and hydrazine units to facilitate ring closure via hydrazone chemistry. This approach yielded a double-layered aromatic arylhydrazone macrocycle with 88% yield. Furthermore, this macrocycle with electron-rich properties showed strong binding to the electron-donor fullerene guest C₆₀ and C₇₀.