Visible-Light Responsive Sucrose-Containing Macrocyclic Host for Cations.

Chiral photoresponsive host was prepared by a high-yield CsCO-templated macrocyclization. - transforms into long-lived - (25 days) upon irradiation with green light, and the backward transformation is triggered by blue light. Both isomers prefer potassium among alkali metal cations, and - binds cations stronger than - (/ ≤ 4.1). H NMR titration experiments as well as density functional theory studies reveal that sucrose ring oxygen residues and azobenzene nitrogen atoms in contribute to cation coordination.