Tri-pillar[5]arene-based multi-stimuli-responsive supramolecular polymers for fluorescence detection and separation of Hg2+

Abstract

A novel tripodal organic gelator (JP5) decorated with three pillar[5]arene tails was designed, synthesized and thoroughly characterized. The stable supramolecular polymer JP5G was obtained within 0.5 minutes by the self-assembly of gelator JP5 in cyclohexanol via C–H⋯π, π⋯π stacking, vdW forces and hydrogen bonding interactions. Interestingly, the supramolecular polymer JP5G showed strong aggregation-induced emission (AIE) and could respond to multiple external stimuli. Simultaneously, JP5G presented special selectivity and high sensitivity for Hg²⁺; the fluorescence detection limit of JP5G for Hg²⁺ is 1.02 × 10⁻⁸ M. In addition, the JP5G xerogel could effectively remove Hg²⁺ from water. What's more, a thin film based on the supramolecular polymer (JP5G) was prepared that could act as a convenient test kit for the detection of Hg²⁺. The use of tri-pillar[5]arene to construct a tripodal pillar[5]arene-based organic gelator constitutes a novel and efficient method for the design and synthesis of novel functional supramolecular polymers.