An amphiphilic water-soluble biphen[3]arene with a tunable lower critical solution temperature behavior

Abstract

Supramolecular macrocycles with a lower critical solution temperature (LCST) behavior have received extensive attention. Exploring a new macrocyclic receptor to achieve a tunable LCST behavior is important for the construction and application of many biorelevant materials. Here we report the first amphiphilic water-soluble thermo-responsive biphen[3]arene bearing tri(ethylene oxide) groups, which shows good LCST behavior in water. The LCST behavior of this macrocyclic receptor in an aqueous solution is tunable by changing its concentration or addition of K⁺. Due to the unique topological structure of biphen[3]arene, the cloud-point temperature of H in 0.500 mM aqueous solution is found to be 26.7 °C, providing an exciting and new design that can be used in many biorelevant fields.