A Series of Layered Assemblies of Hydrogen-Bonded, Hexagonal Networks of <i>C</i>₃‑Symmetric π‑Conjugated Molecules: A Potential Motif of Porous Organic Materials

Hydrogen-bonded porous organic crystals are promising candidates for functional organic materials due to their easy construction and flexibility arising from reversible bond formation–dissociation. However, it still remains challenging to form porous materials with void spaces that are well-controlled in size, shape, and multiplicity because even well-designed porous frameworks often fail to generate pores within the crystal due to unexpected disruption of hydrogen bonding networks or interpenetration of the frameworks. Herein, we demonstrate that a series of C3-symmetric π-conjugated planar molecules (Tp, T12, T18, and Ex) with three 4,4′-dicarboxy-o-terphenyl moieties in their periphery can form robust hydrogen-bonded hexagonal networks (H-HexNets) with dual or triple pores and that the H-HexNets stack without interpenetration to yield a layered assembly of H-HexNet (LA-H-HexNet) with accessible volumes up to 59%. Specifically, LA-H-HexNets of Tp and T12 exhibit high crystallinity and permanent porosity after desolvation (activation): SABET = 788 and 557 m2 g–1, respectively, based on CO2 sorption at 195 K. We believe that the present design principle can be applied to construct a wide range of two-dimensional noncovalent organic frameworks (2D-nCOFs) and create a pathway to the development of a new class of highly porous functional materials.氢键结合多孔有机晶体（Hydrogen-bonded porous organic crystals）因构建流程简便，且凭借可逆键合-解离过程赋予的优异柔性，是极具潜力的功能有机材料候选体系。然而，制备尺寸、形状与孔道多重性均精准可控的多孔材料仍颇具挑战——即便设计精良的多孔框架，也常因氢键网络意外断裂或框架间互穿，导致晶体内部无法形成有效孔道。在此，我们证实一系列外围带有三个4,4'-二羧基邻三联苯基团（4,4′-dicarboxy-o-terphenyl moieties）的C3对称π共轭平面分子（Tp、T12、T18与Ex），可构筑出兼具双孔或三孔结构的稳定氢键六边形网络（H-HexNets）；且该网络不会发生互穿堆叠，最终形成孔可达体积高达59%的氢键六边形网络层状组装体（LA-H-HexNet）。具体而言，Tp与T12的LA-H-HexNet在脱溶剂活化后仍保持高结晶度与永久孔隙率：基于195K下的CO₂吸附测试，其SABET分别为788与557 m²·g⁻¹。我们认为，本研究提出的设计原则可用于构筑各类二维非共价有机框架（2D-nCOFs），为开发新一代高孔隙率功能材料开辟全新路径。