Straightforward supramolecular purification of C84 from a fullerene extract

Abstract

Selective purification of fullerene mixtures via supramolecular encapsulation is an appealing strategy to circumvent the tedious HPLC chromatographic purification protocols. In this work, we utilize tetragonal prismatic nanocapsules of different cavity sizes and shapes to selectively encapsulate C84 from a mixture containing fullerenes ranging from C60 to C96 (fullerene extract), allowing the enrichment of the C84 content from 0.7% to 86%. Moreover, terphenyl-based extra-large nanocapsules were prepared for the first time that can strongly bind the dumbbell-shaped azafullerene dimer (C59N)2 as a guest. Competition experiments between (C59N)2 and C84 allowed the deduction of Ka > 1.0 × 107 M−1 for C84 in nanocapsule 6·(BArF)8. The preference of nanocapsule 7·(BArF)8 to bind C84-D2(22) among all IPR-isomers is also discussed