Sugar-functionalized water-soluble pillar[5] arene and its host-guest interaction with fullerene

Pillar[5] arenes have attracted much attention as a new member of macrocycles due to their unique symmetrical pillar architecture. Pillar[5] arenes are mostly soluble in organic solvents and slightly soluble in water, thus their application in aqueous media has been limited as a result. It is therefore necessary to design water-soluble pillar[5] arene derivatives. Herein, by the introduction of neutral sugar moieties at both upper and lower rims via click reaction, a neutral water-soluble pillar[5] arene (P5AG) was prepared and characterized well. Furthermore, the host-guest interaction between P5AG and fullerene was investigated in both organic medium and aqueous solution. The host-guest complexation was confirmed by fluorescence, nuclear magnetic resonance, ultraviolet-visible, and Raman spectroscopy.