Song Ziye, Liu Linghao, Sun Qian, Du Jingcheng, Guan Jian, Dou Pengjia, Zhang Runnan, Jiang Zhongyi, Liu Jiangtao
Department of Environmental Science and Engineering, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei, 230026, China.
Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Angew Chem Int Ed Engl. 2024 Sep 16;63(38):e202409296. doi: 10.1002/anie.202409296. Epub 2024 Aug 7.
Among the various types of materials with intrinsic porosity, porous organic cages (POCs) are distinctive as discrete molecules that possess intrinsic cavities and extrinsic channels capable of facilitating molecular sieving. However, the fabrication of POC membranes remains highly challenging due to the weak noncovalent intermolecular interactions and most reported POCs are powders. In this study, we constructed crystalline free-standing porous organic cage membranes by fortifying intermolecular interactions through the induction of intramolecular hydrogen bonds, which was confirmed by single-crystal X-ray analysis. To elucidate the driving forces behind, a series of terephthaldehyde building blocks containing different substitutions were reacted with flexible triamine under different conditions via interfacial polymerization (IP). Furthermore, density functional theory (DFT) calculations suggest that intramolecular hydrogen bonding can significantly boost the intermolecular interactions. The resulting membranes exhibited fast solvent permeance and high rejection of dyes not only in water, but also in organic solvents. In addition, the membrane demonstrated excellent performance in precise molecular sieving in organic solvents. This work opens an avenue to designing and fabricating free-standing membranes composed of porous organic materials for efficient molecular sieving.
在各种具有固有孔隙率的材料中，多孔有机笼（POC）作为离散分子具有独特性，其具有能够促进分子筛分的固有腔和外部通道。然而，由于弱的非共价分子间相互作用，POC膜的制备仍然极具挑战性，并且大多数报道的POC都是粉末状。在本研究中，我们通过诱导分子内氢键来强化分子间相互作用，构建了结晶性自支撑多孔有机笼膜，这一点通过单晶X射线分析得到了证实。为了阐明其背后的驱动力，一系列含有不同取代基的对苯二甲醛结构单元在不同条件下通过界面聚合（IP）与柔性三胺反应。此外，密度泛函理论（DFT）计算表明分子内氢键可以显著增强分子间相互作用。所得膜不仅在水中，而且在有机溶剂中都表现出快速的溶剂渗透率和对染料的高截留率。此外，该膜在有机溶剂中的精确分子筛分方面表现出优异性能。这项工作为设计和制造由多孔有机材料组成的用于高效分子筛分的自支撑膜开辟了一条途径。
