A Copper-based Supramolecular Nanocapsule that Enables Straightforward Purification of Sc₃ N-based Endohedral...

A self-assembled Cu^II -based nanocapsule enables efficient and straightforward isolation of Sc₃ N@C₈₀ from arc-processed raw soot. The newly designed Cu^II -based supramolecular nanocapsule 5⋅(OTf)₈ was used to effectively entrap fullerenes and endohedral metallofullerenes (EMFs) with different affinities depending on their size and shape. Moreover, we took advantage of the sharply different entrapment abilities of the 5⋅(OTf)₈ cage in the solid state versus in solution to encapsulate all the species with the exception of Sc₃ N@C₈₀ (both I_h and D_5h isomers), which remains pure in solution. HPLC quantification determined that up to 85 % of the total Sc₃ N@C₈₀ content in the initial mixture was recovered in very high purity (>99.5 %). The complete release of the encapsulated species with an orthogonal solvent-washing strategy regenerates 5⋅(OTf)₈ ready to be re-used. This approach opens new opportunities for EMFs purification.