Atomically resolved imaging of radiation-sensitive metal-organic frameworks via electron ptychography

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 22, 2025

Electron ptychography, recognized as an ideal technique for low-dose imaging, consistently achieves deep sub-angstrom resolution at electron doses of several thousand electrons per square angstrom (e−/Å2) or higher. Despite its proven efficacy, the application ptychography even lower doses—necessary materials highly sensitive to beams—raises questions regarding feasibility and attainable under such stringent conditions. Herein, we demonstrate implementation near-atomic-resolution ( ~ 2 Å) reconstruction low ~100 e−/Å2, metal-organic frameworks (MOFs), which are known their extreme sensitivity. The reconstructed images clearly resolve organic linkers, metal clusters, atomic columns within these while unravelling various local structural features in MOFs, including missing extra surface termination modes. By combining findings from simulations experiments, have identified that employing a small convergence semi-angle during data acquisition is crucial effective iterative ptychographic This important insight advances our understanding rapidly evolving provides novel approach high-resolution imaging materials. study investigates optimal 4D-STEM parameters achieving e−/Å2 on framework

Language: Английский

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Giant Enhancement of Optical Nonlinearity by Manipulating Guest Molecular Stacking Modes in Metal–Organic Frameworks

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 4, 2025

The influence of guest stacking interactions in host-guest (H-G) MOF composites on third-order nonlinear optical (NLO) performance remains largely unknown. Herein, we propose for the first time a noncovalent aggregate confinement strategy synthesizing H-G with different modes. And [perylene2]n (α-Pe) and [perylene]n (β-Pe) were selected as guests confined into novel Ca-based {[Ca(TBAPy)(DMA)2]·3DMA·[N(CH3)2]·H2O}n (Ca-MOF-pts). NLO results showed that compared to β-Pe@Ca-MOF-pts, saturable absorption (SA) self-defocusing properties α-Pe@Ca-MOF-pts increased by 2.71-fold 3.82-fold, respectively. Interestingly, α/β-Pe@Ca-MOF-pts can be transformed α/β-Pe@Ca-MOF-flu (Ca-MOF-flu = {[Ca1.5(TBAPy)(H2O)2]·DMA·[N(CH3)2]·2H2O}n) through self-adaptive topological evolution, corresponding signal change from SA reverse (RSA). As expected, β-Pe@Ca-MOF-flu, RSA α-Pe@Ca-MOF-flu are improved 2.94-fold 4.07-fold, respectively, demonstrating importance Theoretical calculation transient spectra indicated enhancement was attributed large π-π overlap α-Pe, which promoted electron delocalization/transfer optimized cross-sectional ground state excited state. This study provides new developing excellent properties.

Language: Английский

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Polar alcohol guest molecules regulate the stacking modes of 2-D MOF nanosheets

Chemical Science, Journal Year: 2024, Volume and Issue: 15(11), P. 4106 - 4113

Published: Jan. 1, 2024

The modulation of two-dimensional metal-organic framework (2-D MOF) nanosheet stacking is an effective means to improve the properties and promote application nanosheets in various fields. Here, we employed a series alcohol guest molecules (MeOH, EtOH PrOH) modulate Zr-BTB (BTB = benzene-1,3,5-tribenzoate) generate untwisted stacking. distribution angles was statistically analyzed from high-angle annular dark-field (HAADF) fast Fourier transform (FFT) images. ratios were calculated, such as 77.01% for MeOH, 83.45% EtOH, 85.61% PrOH. obtained showed good separation abilities different substituted benzene isomers, superior para selectivity excellent column stability reusability. Control experiments 2-D Zr-TCA (TCA 4,4',4''-tricarboxytriphenylamine) Zr-TATB (TATB 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tribenzoic acid) with similar pore sizes stronger polarity regulated by guests exhibited moderate performance. electron microscopy images revealed that polar regulation dominantly generated twisted Moiré patterns. Polar molecules, alcohols, provide strong host-guest interactions during MOF stacking, providing opportunity design new porous materials prospects.

Language: Английский

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Metal–organic frameworks for the separation of xylene isomers

Chemical Society Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Xylene isomers, including

Language: Английский

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Enhanced Stability and Separation Resolution of Gas Chromatographic Stationary Phases via Nano-MIL-103 Fabrication

Talanta, Journal Year: 2025, Volume and Issue: 287, P. 127665 - 127665

Published: Jan. 29, 2025

Language: Английский

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Untwisting Strategy of MOF Nanosheets in Ultrathin Film Membrane for High Molecular Separation Performance

Small, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 31, 2025

Oriented 2D metal-organic framework (MOF) membranes hold considerable promise for industrial separation processes. Nevertheless, the lattice misalignment caused by twisted stacking of nanosheets reduces in-plane pore size and exerts a significant impact on membrane performance. Precisely regulating pattern oriented MOF remains challenge. Here, scalable scrape-coating technique supplemented vapor untwisting strategy is proposed to directly construct non-twisted ultrathin Zr-BTB (Zr-BTB-M) polyvinylidene fluoride (PVDF) substrates. The are induced undergo reorganization during coating process, resulting in highly overlapped lattices largest channels. exceptional butyl acetate selective adsorption capacity Zr-BTB, combined with its provision ordered vertical penetrating pathways, significantly enhances molecular transport. After facile polydimethylsiloxane (PDMS) coating, pervaporation index PDMS/Zr-BTB-M/PVDF found be 9.74 times higher than that conventional PDMS/PVDF membranes, paving way innovative, high-efficiency, energy-saving technologies.

Language: Английский

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Postsynthetic Modification of Metal–Organic Layers

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: March 6, 2025

ConspectusMetal-organic layers (MOLs), as a subclass of two-dimensional (2D) metal-organic frameworks (MOFs), have gained prominence in materials science by combining the structural versatility MOFs with unique physical and chemical properties 2D materials. MOLs consist metal oxide clusters connected organic ligands, forming periodically extended architectures tunable large surface areas. These characteristics endow significant potential for applications catalysis, sensing, energy storage, biomedicine.The synthesis predominantly follows two key pathways: top-down exfoliation bulk layered bottom-up assembly from molecular building units. The method allows isolation ultrathin MOL sheets precursors, but scalability defects present ongoing challenges. In contrast, offers more precise control over design, enabling formation tailored functionalities morphologies. By carefully selecting linkers synthetic conditions, researchers successfully constructed diverse geometric configurations including linear, triangular, rectangular ligand motifs. Nevertheless, achieving consistent monolayer controlling lateral dimensions remain critical challenges widespread application these materials.A defining advantage is their exceptional amenability to postsynthetic modification (PSM). PSM strategies enable fine-tuning introduction novel without compromising integrity underlying framework. Four principal approaches been established: (1) linker modification, where additional coordination sites facilitate selective metalation or functional group incorporation; (2) secondary unit (SBU) using replaceable perpendicular plane targeted functionalization; (3) dual integrating SBU functionalization achieve complex multifunctional platforms; (4) multilevel assembly, incorporating into larger hierarchical such biomimetic systems composite materials.These versatile unlocked MOLs, single-site photocatalysis, artificial photosynthetic systems. For instance, functionalized transition complexes accessible reactive than conventional faster substrate transport. Additionally, interfaced systems, liposomes proteins, demonstrated promise photochemical conversion oxidation processes.Despite advancements, several obstacles persist. Achieving uniform thickness while preventing multilayer aggregation remains formidable task, necessitating deeper insights thermodynamic kinetic factors governing growth. Furthermore, behavior during drying, adsorption, often deviates classical models, suggesting involvement interfacial phenomena that warrant further investigation. Addressing will be crucial harnessing full next-generation materials.In summary, represent dynamic class offer opportunities innovation across scientific disciplines. advancing methodologies deepening our understanding strategies, can continue expand landscape paving way transformative conversion, beyond.

Language: Английский

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Directional Regulation of One-Dimensional Channel Length in Metal-Organic Frameworks for Efficient Xylene Isomer Separation in Gas Chromatography

Analytica Chimica Acta, Journal Year: 2025, Volume and Issue: unknown, P. 343957 - 343957

Published: March 1, 2025

Language: Английский

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Two-dimensional metal–organic framework for post-synthetic immobilization of graphene quantum dots for photoluminescent sensing

Communications Chemistry, Journal Year: 2024, Volume and Issue: 7(1)

Published: May 11, 2024

Abstract Immobilization of graphene quantum dots (GQDs) on a solid support is crucial to prevent GQDs from aggregation in the form powder and facilitate separation recycling after use. Herein, spatially dispersed are post-synthetically coordinated within two-dimensional (2D) water-stable zirconium-based metal–organic framework (MOF). Unlike pristine GQDs, obtained immobilized 2D MOF sheets show photoluminescence both suspension dry powder. Chemical photoluminescent stabilities MOF-immobilized water investigated, use detection copper ions demonstrated. Findings here shed light MOFs as platform further immobilize with various sizes distinct chemical functionalities for range applications.

Language: Английский

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Successively Controlling Nanoscale Wrinkles of Ultrathin 2D Metal‐Organic Framework Nanosheets

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: July 27, 2024

The wrinkles are pervasive in ultrathin two-dimensional (2D) materials, but the regulation of is rarely explored systematically. Here, we employed a series carboxylic acids (from formic acid to octanoic acid) control Zr-BTB (BTB=1, 3, 5-(4-carboxylphenyl)-benzene) metal-organic framework (MOF) nanosheet. at micrometer scale were observed with transmission electron microscopy. Furthermore, high-angle annular dark-field (HAADF) images showed lattice distortion many nanoscale regions, which was precisely matched nano-wrinkles. With changes hydrophilicity/hydrophobicity, MOF-MOF and MOF-solvent interactions possibly synergistically regulated different sizes obtained, supported by HAADF, molecular dynamics, density functional theory calculation. Different wrinkle resulted pore between nanosheet interlayers, providing highly-oriented thin films successive optimization kinetic diffusion pathways, proved grazing-incidence wide-angle X-ray scattering nitrogen adsorption. most suitable from Zr-BTB-C

Language: Английский

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