Molecular Tweezer Based on Perylene and Crown Ether for Selective Recognition of Fullerenes.

A molecular tweezer -di(perylene-3-ylmethanaminobenzo)-18-crown-6 (DP-18C6) incorporating two perylene subunits in a single crown ether core was designed and synthesized as a host for fullerenes. Through the cooperative effect of the perylene subunits and the crown ether moiety, DP-18C6 can efficiently recognize fullerenes including C, C, and C. H NMR titration and fluorescence titration experiments demonstrated that DP-18C6 can effectively grasp the fullerene molecule to form a 1:1 host-guest complex. Density functional theory calculations revealed the presence of intermolecular π-π interactions between the perylene subunits of DP-18C6 and the fullerene molecule. More importantly, DP-18C6 exhibited remarkably high binding selectivity for higher fullerenes over C, revealing potential application for the separation of fullerenes by means of host-guest interactions.