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To efficiently capture the toxic uranyl ions (UO22+), a new hierarchical micro‐macroporous metal–organic framework was prepared under template‐free conditions, featuring interconnected multi‐nanocages bearing carbonyl groups derived from a semi‐rigid ligand. The material exhibits an unusually high UO22+ sorption capacity of 562 mg g?1, which occurs in an intriguing two‐steps process, on the macropore‐based crystal surface and in the inner nanocages. Notably, the latter is attributed to the cooperative interplay of the shrinkage of the host porous framework induced by uranyl accommodation and the free carbonyl coordination sites, as shown by both single‐crystal X‐ray diffraction and a red‐shift of the infrared [O=UVI=O]2+ antisymmetric vibration band.  相似文献   

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Given the unique structural and electronic properties of C60, metal–organic frameworks (MOFs) containing C60 linkers are expected to exhibit interesting characteristics. A new hexakisfullerene derivative possessing two pairs of phenyl pyridine groups attached to two methano‐carbon atoms located at the trans‐1 positions was designed and synthesized. The four pyridyl nitrogen atoms define a perfectly planar rectangle. This new C60 derivative was used to assemble the first fullerene‐linked two‐dimensional MOF by coordination with Cd2+.  相似文献   

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A novel 3D metal‐organic framework BSF‐1 based on the closo‐dodecaborate cluster [B12H12]2? was readily prepared at room temperature by supramolecular assembly of CuB12H12 and 1,2‐bis(4‐pyridyl)acetylene. The permanent microporous structure was studied by X‐ray crystallography, powder X‐ray diffraction, IR spectroscopy, thermogravimetric analysis, and gas sorption. The experimental and theoretical study of the gas sorption behavior of BSF‐1 for N2, C2H2, C2H4, CO2, C3H8, C2H6, and CH4 indicated excellent separation selectivities for C3H8/CH4, C2H6/CH4, and C2H2/CH4 as well as moderately high separation selectivities for C2H2/C2H4, C2H2/CO2, and CO2/CH4. Moreover, the practical separation performance of C3H8/CH4 and C2H6/CH4 was confirmed by dynamic breakthrough experiments. The good cyclability and high water/thermal stability render it suitable for real industrial applications.  相似文献   

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Enhancing thermal and chemical durability and increasing surface area are two main directions for the construction and improvement of the performance of porous hydrogen‐bonded organic frameworks (HOFs). Herein, a hexaazatriphenylene (HAT) derivative that possesses six carboxyaryl groups serves as a suitable building block for the systematic construction of thermally and chemically durable HOFs with high surface area through shape‐fitted docking between the HAT cores and interpenetrated three‐dimensional network. A HAT derivative with carboxybiphenyl groups forms a stable single‐crystalline porous HOF that displays protic solvent durability, even in concentrated HCl, heat resistance up to 305 °C, and a high Brunauer–Emmett–Teller surface area [SA(BET)] of 1288 m2 g−1. A single crystal of this HOF displays anisotropic fluorescence, which suggests that it would be applicable to polarized emitters based on robust functional porous materials.  相似文献   

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We describe an example of “interpenetration isomerism” in three‐dimensional hydrogen‐bonded organic frameworks. By exploiting the crystallization conditions for a peripherally extended triptycene H6PET, we can modulate the interpenetration of the assembled frameworks, yielding a two‐fold interpenetrated structure PETHOF‐ 1 and a five‐fold interpenetrated structure PETHOF‐ 2 as interpenetration isomers. In PETHOF‐ 1 , two individual nets are related by inversion symmetry and form an interwoven topology with a large guest‐accessible volume of about 80 %. In PETHOF‐ 2 , five individual nets are related by translational symmetry and are stacked in an alternating fashion. The activated materials show permanent porosity with Brunauer‐Emmett‐Teller surface areas exceeding 1100 m2 g?1. Synthetic control over the framework interpenetration could serve as a new strategy to construct complex supramolecular architectures from simple organic building blocks.  相似文献   

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A robust hydrogen‐bonded organic framework HOF‐TCBP (H4TCBP=3,3′,5,5′‐tetrakis‐(4‐carboxyphenyl)‐1,1′‐biphenyl) has been successfully constructed and structurally characterized. It possesses a permanent 3D porous structure with a 5‐fold interpenetrated dia topological network. This activated HOF‐TCBP has a high BET surface area of 2066 m2 g−1 and is capable of highly selective adsorption and separation of light hydrocarbons under ambient conditions. It shows excellent thermal stability, as demonstrated by PXRD experiments and N2 adsorption tests. Practical use of HOF‐TCBP is facilitated by the ease of its preparation and renewal through rotary evaporation.  相似文献   

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Metal halide perovskites have emerged as a new generation of X‐ray detector materials. However, large‐sized MAPbI3 single crystals (SCs) still exhibit lower performance than MAPbBr3 SCs in X‐ray detection. DFT (density functional theory) simulations suggest the problem could be overcome by alloying large‐sized cations at the A site. The alloyed process could notably decrease the electron–phonon coupling strength and increase the material defect formation energy. Accordingly, centimeter‐sized alloyed DMAMAPbI3 (DMA=dimethylammonium) and GAMAPbI3 (GA=guanidinium) SCs are obtained. Electrical characterizations confirm the GAMAPbI3 SCs display improved charge collection efficiency. It also exhibits a remarkable reduction of dark current, an important figure of merit for X‐ray detectors. With a judiciously designed device architecture, the overall detector performance confirms GAMAPbI3 SCs as one of the most sensitive perovskite X‐ray detectors to date.  相似文献   

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