Unique Separation Behavior of a C₆₀ Fullerene-Bonded Silica Monolith Prepared by an Effective Thermal Coupling Agent

Herein, we report a newly developed C₆₀ fullerene-bonded silica monolith in a capillary with unique retention behavior due to the structure of C₆₀ fullerene. N-Hydroxysuccinimide (NHS)-conjugated C₆₀ fullerene was successfully synthesized by a thermal coupling agent, perfluorophenyl azide (PFPA), and assigned by spectroscopic analyses. Then, NHS-PFPA-C₆₀ fullerene was attached onto the surface of a silica monolith in a capillary. The capillary provided specific separation ability for polycyclic aromatic hydrocarbons in liquid chromatography by an effective π-π interaction. Furthermore, corannulene, which has a hemispherical structure, was selectively retained in the capillary based on the specific structural recognition due to the spherical C₆₀ fullerene. This is the first report revealing the spherical recognition ability by C₆₀ fullerene in liquid chromatographic separation. Spherical recognition: A C₆₀ fullerene-bonded silica monolithic medium was prepared by using a thermal coupling agent conjugated with C₆₀ fullerene. The C₆₀ fullerene-bonded monolith prepared in a capillary showed a very strong π-π interaction in liquid chromatography. Also, the hemispherical molecule corannulene was dramatically retained in the C₆₀ fullerene-bonded monolith by the unique molecular recognition based on a buckyball (see figure).