Molecular recognition by a silica-bound fullerene derivative

Thermal ring opening of N-[3-(triethoxysilyl)propyl]-2-carbomethoxyaziridine in the presence of C-60 produces a fulleropyrrolidine derivative which is then attached covalently to HPLC silica gel. The new chromatographic material is used to investigate binding affinities of potential hosts for the immobilized C-60. Exceptionally high size selectivities have been obtained for cyclic oligomeric compounds like calixarenes and cyclodextrins in organic and water-rich media, respectively. A number of rationally designed, helical-shaped peptides bind selectively to the grafted fullerene. The mast tightly bound peptide carries two ferrocene moieties at the periphery of a hydrophobic binding cavity complementary in size to C-60.