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Two copolymers are synthesized: one (P1) has pendant azo and 5‐(1H‐1, 2, 3‐triazol‐1‐yl) pentanenitrile (TAPN) groups, and the other (P2) has pendant azo and pillar[5]arene groups. When the two copolymers are mixed in chloroform, an organogel with excellent self‐healing capability and dual‐stimulus responsiveness is formed. Reversible double noncovalent cross‐linked networks including host–guest complexation and π–π interactions are responsible for this property. A xerogel prepared from the organogel can capture iodine in aqueous media. The presence of many effective sorption sites including electron‐rich phenolic units and azo groups provides the xerogel with iodine uptake ability. The pillar[5]arene‐based gel can adsorb iodine and self‐heal rapidly, and therefore has potential as a long‐life adsorbent. [ABSTRACT FROM AUTHOR]

A copolymer with pillar[5]arenes as the pendant groups and a homoditopic guest bearing two triazole‐containing cyanoalkane groups are synthesized. Mixing the copolymers and the guests, a self‐healing gel comes into being. The gel self‐heals immediately and recovers completely within 90 s. It can respond to temperature and competitive molecules. It also exhibits favorable mechanical and remolding properties. Further investigations show that the strong host–guest interaction between pillar[5]arene and the guest is responsible for the excellent properties of the gel. Azobenzene motifs in guest may improve the hardness and moldability of the gel. As far as it is known, such rapid and efficient healing is unprecedented. [ABSTRACT FROM AUTHOR]

The binding selectivity of an adenine-monofunctionalized pillar[5]arene (H) with a series of pyrimidine derivatives were investigated through 1H NMR experiments and density functional theory (DFT) study. High binding-selectivity was demonstrated. Typically, H displayed very strong binding strength with 6-(2,4-dioxo-3, 4-dihydropyrimidin-1 (2H)-yl)hexanenitrile (G1) [Ka >105 M−1], up to about 3000-fold as compared with 1-hexylpyrimidine-2,4(1H, 3H)-dione (G5) [Ka = 31 M−1]. The strong binding ability of H with G1 was due to the cooperative multiple hydrogen bond, dipole-dipole, C-H···π and π···π interactions. The high binding-selectivity was also verified by calculation results. The calculated interaction energy (ΔEi) of G1⊂H was −12.92 Kcal·mol−1 while that of G5⊂H was −2.85 Kcal·mol−1. [ABSTRACT FROM AUTHOR]