Megalo‐Cavitands: Synthesis of Acridane[4]arenes and Formation of Large, Deep Cavitands for Selective C70 Uptake

Deep cavitands, concave molecular containers, represent an important supramolecular host class that has been explored for a variety of applications ranging from sensing, switching, purification and adsorption to catalysis. A major limitation in the field has been the cavitand volume that is restricted by the size of the structural platform utilized (diameter approx. 7 Å). We here report the synthesis of a novel, unprecedentedly large structural platform, named acridane[4]arene (diameter approx. 14 Å), suitable for the construction of cavitands with volumes of up to 814 Å3. These megalo‐cavitands serve as size‐selective hosts for fullerenes with mM to sub‐μM binding affinity for C60 and C70. Furthermore, the selective binding of fullerene C70 in the presence of C60 was demonstrated. An unprecedentedly large structural platform, named acridane[4]arene (diameter approx. 14 Å), synthesized in only six steps, has been shown to be suitable for the construction of cavitands with volumes of up to 814 Å3. These megalo‐cavitands serve as size‐selective hosts for fullerenes with sub‐μM binding affinity for C70.