Control of LCST phase transition behaviour of phosphonium-based ionic liquids in water using supramolecular host–guest chemistry

Abstract

Some phosphonium-based ionic liquids exhibit LCST phase transition behaviour in water. This study demonstrates that host–guest interactions obtained by adding an α-cyclodextrin host increased their LCST phase transition temperature (T_LCST). NMR analysis confirmed the complex formation between the phosphonium cation and α-cyclodextrin that drives the drastic change of T_LCST.