Solid-state self-inclusion complexation behaviour of a pillar[5]arene-based host–guest conjugate

Abstract

A host–guest conjugate consisting of a pillar[5]arene and an ethylene moiety containing a triazole group at one end and a perfluorooctyl group at the other end was synthesized. The host–guest conjugate displayed unusual real-time scale solid-state self-inclusion complexation behaviour. The host–guest conjugate formed a de-threaded supramolecular structure only in solution, even at high concentrations. However, heating the solid-state host–guest conjugate led to the formation of a self-inclusion complex structure at a real-time scale; at 100 °C, it took ca. 20 h to form the self-inclusion complex at the equilibrium state at a conversion of 85%. The self-inclusion complex converted to the de-threaded form at a real-time scale when it was stored in solvents with small molecules, which worked as competitive guests.