Host–guest interactions of a twisted cucurbit[15]uril with paraquat derivatives and bispyridinium salts

Abstract Host–guest complexations of a twisted cucurbit[15]uril with some paraquat derivatives and bispyridinium salts in aqueous solution are investigated by nuclear magnetic resonance, UV–vis spectrometry and isothermal titration calorimetry. These complexations are mainly enthalpy-driven.