Robust Supramolecular Nano-Tunnels Built from Molecular Bricks**

作者：Wei, Peifa^*; He, Xuan; Zheng, Zheng; He, Donglin; Li, Qiyao; Gong, Junyi; Zhang, Jun; Sung, Herman H. Y.; Williams, Ian D.; Lam, Jacky W. Y.; Liu, Ming^*; Tang, Ben Zhong^*

来源：Angewandte Chemie - International Edition, 2021, 60(13): 7148-7154.

DOI：10.1002/anie.202013117

• aggregation-induced emission
• CO2 adsorption
• crystal transformations
• linear organic salts
• porous molecular crystals

Herein we report a linear ionic molecule that assembles into a supramolecular nano-tunnel structure through synergy of trident-type ionic interactions and pi-pi stacking interactions. The nano-tunnel crystal exhibits anisotropic guest adsorption behavior. The material shows good thermal stability and undergoes multi-stage single-crystal-to-single-crystal phase transformations to a nonporous structure on heating. The material exhibits a remarkable chemical stability under both acidic and basic conditions, which is rarely observed in supramolecular organic frameworks and is often related to structures with designed hydrogen-bonding interactions. Because of the high polarity of the tunnels, this molecular crystal also shows a large CO2-adsorption capacity while excluding other gases at ambient temperature, leading to high CO2/CH4 selectivity. Aggregation-induced emission of the molecules gives the bulk crystals vapochromic properties.