A pillar[5]arene-based multiple-stimuli responsive metal–organic gel was constructed for facile removal of mercury ions

Abstract

A thioacetohydrazide functionalized pillar[5]arene was synthesized, which could further assemble into a linear supramolecular metal–organic polymer upon adding Zn²⁺. Furthermore, the obtained linear supramolecular metal–organic polymer could self-assemble to form a fluorescent supramolecular metal–organic gel at high concentration. When TBAOH was added to the viscous solution at high temperature, the obtained solution could not form a supramolecular metal–organic gel upon cooling. More importantly, when Hg²⁺ ions are added to the metal–organic gel, the strong blue fluorescence is clearly quenched, and this metal–organic gel (xerogel) could effectively remove Hg²⁺ from water. Simultaneously, a thin film based on the metal–organic gel was prepared, which was confirmed to be a convenient test kit for detecting Hg²⁺.