Thermally Bisignate\nAnion Responsive Supramolecular\nGel and <i>In Situ</i> Generation of a Conductive Hybrid-Gel\nNanocomposite

Understanding\nthe structure–function relationship is a significant\nchallenge in designing supramolecular soft materials such as supramolecular\ngels. To address this challenge, we report on two urea-based dipodal\nligands, <b>PY-NAP</b> and <b>PY-CF</b><sub><b>3</b></sub>, with different terminal substituents influencing their gelation\nproperties. The terminal substituents play a crucial role in the gelation\nabilities. The gel formed from <b>PY-NAP</b> exhibited notably\nhigh thermal stability and displayed a unique “thermally bisignate”\nbehavior. Both ligands contain urea and amide units, allowing them\nto encapsulate the SO<sub>4</sub><sup>2–</sup> anion in their\npincer cavities in the solid state. The solid-state anion recognition\nprinciple is used to construct a selective anion-responsive supramolecular\ngel. Additionally, the gel was used to sequester precious metal salts\nfrom aqueous solutions, achieving an uptake efficiency of over 90%,\nfollowed by <i>in situ</i> reduction to form nanoparticles.\nThis concept was then applied to create a conductive supramolecular\nhybrid gel nanocomposite with significantly high conductivity, holding\nsignificant implications for industrial and environmental applications.