A small aperture enabling capsulation of HF inside [60]fullerene

Abstract

A small aperture, which allows for HF to be encapsulated, was prepared on [60]fullerene. For its preparation, we applied reductive decarbonylation to an opened [60]fullerene bearing an aperture with a ring-atom count of 13, leading to two major derivatives with an aperture consisting of 14 atoms. We found that a chemical structure of the aperture is crucial to determine the selectivity between the two. Since the reaction was carried out at 180 °C in the presence of water, the products spontaneously accommodate a water molecule through the aperture. Under rather milder conditions at 0 °C, however, HF was encapsulated within the cavity. We were aware of unusual shifting of proton signals upon encapsulation of HF. This is owing to translational movement of HF within the cavity as suggested by theoretical calculations.