Visible-Light Responsive Sucrose-Containing Macrocyclic Host for Cations

Chiral photoresponsive host 1 was prepared by a high-yield Cs2CO3-templated macrocyclization. Trans-1 transforms into long-lived cis-1 (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 cis-1 binds cations stronger than trans-1 (K-cis/K-trans <= 4.1). H-1 NMR titration experiments as well as density functional theory studies reveal that sucrose ring oxygen residues and azobenzene nitrogen atoms in 1 contribute to cation coordination.

Automated summary

A chiral photoresponsive host 1 was prepared with high yield through Cs2CO3-templated macrocyclization. Upon green light irradiation, Trans-1 transforms into long-lived cis-1 (25 days), with the backward transformation triggered by blue light. Both isomers exhibit a preference for potassium among alkali metal cations, and cis-1 binds cations more strongly than trans-1 (K-cis/K-trans <= 4.1).