A Molecular Scoop for Higher Fullerenes

Significance

A macrocycle, which preferably binds higher fullerenes, is synthesized and then used to extract an array of higher fullerenes from a mixture, which is predominantly C₆₀. The macrocycle is formed as a mixture of syn and anti isomers that are easily separated by filtration. The syn conformation forms complexes with higher fullerenes, which can be isolated when they precipitate. Upon heating, the macrocycle host undergoes a conformational change to the anti form, releasing the guest fullerenes.