Probing Molecular Motions in Metal–Organic Frameworks by Three-Dimensional Electron Diffraction

Three-dimensional electron diffraction (3DED) has been proven as an effective and accurate method for structure determination of nano-sized crystals. In the past decade, the crystal structures of various new complex metal-organic frameworks (MOFs) have been revealed by 3DED, which has been the key to understand their properties. However, due to the design of transmission electron microscopes (TEMs), one drawback of 3DED experiments is the limited tilt range of goniometer, which often leads to incomplete 3DED data, particularly when the crystal symmetry is low. This drawback can be overcome by high throughput data collection using continuous rotation electron diffraction (cRED), where data from a large number of crystals can be collected and merged. Here, we investigate the effects of improving completeness on structural analysis of MOFs. We use ZIF-EC1, a zeolitic imidazolate framework (ZIF), as an example. ZIF-EC1 crystallizes in a monoclinic system with a plate-like morphology. cRED data of ZIF-EC1 with different completeness and resolution were analyzed. The data completeness increased to 92.0% by merging ten datasets. Although the structures could be solved from individual datasets with a completeness as low as 44.5% and refined to a high precession (better than 0.04 Å), we demonstrate that a high data completeness could improve the structural model, especially on the electrostatic potential map. We further discuss the strategy adopted during data merging. We also show that ZIF-EC1 doped with cobalt can act as an efficient electrocatalyst for oxygen reduction reaction.

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On the Completeness of Three-Dimensional Electron Diffraction Data for Structural Analysis of Metal-Organic Frameworks

Faraday Discussions ◽

10.1039/d1fd00020a ◽

2021 ◽

Author(s):

Meng Ge ◽

Taimin Yang ◽

Yanzhi Wang ◽

Francesco Carraro ◽

Weibin Liang ◽

...

Keyword(s):

Structural Analysis ◽

Electron Diffraction ◽

Metal Organic Frameworks ◽

Three Dimensional ◽

Accurate Method ◽

Electron Diffraction Data ◽

Dimensional Electron ◽

The Past ◽

Metal Organic

Three-dimensional electron diffraction (3DED) has been proven as an effective and accurate method for structure determination of nano-sized crystals. In the past decade, the crystal structures of various new complex...

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On the Completeness of Three-Dimensional Electron Diffraction Data for Structural Analysis of Metal-Organic Frameworks

10.26434/chemrxiv.14213966 ◽

2021 ◽

Author(s):

Meng Ge ◽

Taimin Yang ◽

Yanzhi Wang ◽

Francesco Carraro ◽

Weibin Liang ◽

...

Keyword(s):

Structural Analysis ◽

Electron Diffraction ◽

Structural Model ◽

Metal Organic Frameworks ◽

Three Dimensional ◽

Electron Diffraction Data ◽

Dimensional Electron ◽

Data Completeness ◽

Continuous Rotation ◽

Metal Organic

Three-dimensional electron diffraction (3DED) has been proven as an effective and accurate method for structure determination of nano-sized crystals. In the past decade, the crystal structures of various new complex metal-organic frameworks (MOFs) have been revealed by 3DED, which has been the key to understand their properties. However, due to the design of transmission electron microscopes (TEMs), one drawback of 3DED experiments is the limited tilt range of goniometer, which often leads to incomplete 3DED data, particularly when the crystal symmetry is low. This drawback can be overcome by high throughput data collection using continuous rotation electron diffraction (cRED), where data from a large number of crystals can be collected and merged. Here, we investigate the effects of improving completeness on structural analysis of MOFs. We use ZIF-EC1, a zeolitic imidazolate framework (ZIF), as an example. ZIF-EC1 crystallizes in a monoclinic system with a plate-like morphology. cRED data of ZIF-EC1 with different completeness and resolution were analyzed. The data completeness increased to 92.0% by merging ten datasets. Although the structures could be solved from individual datasets with a completeness as low as 44.5% and refined to a high precession (better than 0.04 Å), we demonstrate that a high data completeness could improve the structural model, especially on the electrostatic potential map. We further discuss the strategy adopted during data merging. We also show that ZIF-EC1 doped with cobalt can act as an efficient electrocatalyst for oxygen reduction reaction.

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On the completeness of three-dimensional electron diffraction data for structural analysis of metal–organic frameworks

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s0108767321096872 ◽

2021 ◽

Vol 77 (a1) ◽

pp. a312-a312

Author(s):

Meng Ge ◽

Xiaodong Zou

Keyword(s):

Structural Analysis ◽

Electron Diffraction ◽

Diffraction Data ◽

Metal Organic Frameworks ◽

Three Dimensional ◽

Electron Diffraction Data ◽

Dimensional Electron ◽

Metal Organic

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Three-Dimensional Electron Diffraction for Structural Analysis of Beam-Sensitive Metal-Organic Frameworks

Crystals ◽

10.3390/cryst11030263 ◽

2021 ◽

Vol 11 (3) ◽

pp. 263

Author(s):

Meng Ge ◽

Xiaodong Zou ◽

Zhehao Huang

Keyword(s):

High Resolution ◽

Electron Diffraction ◽

Data Quality ◽

Metal Organic Frameworks ◽

Three Dimensional ◽

Electron Diffraction Data ◽

X Rays ◽

Dimensional Electron ◽

Continuous Rotation ◽

Metal Organic

Electrons interact strongly with matter, which makes it possible to obtain high-resolution electron diffraction data from nano- and submicron-sized crystals. Using electron beam as a radiation source in a transmission electron microscope (TEM), ab initio structure determination can be conducted from crystals that are 6–7 orders of magnitude smaller than using X-rays. The rapid development of three-dimensional electron diffraction (3DED) techniques has attracted increasing interests in the field of metal-organic frameworks (MOFs), where it is often difficult to obtain large and high-quality crystals for single-crystal X-ray diffraction. Nowadays, a 3DED dataset can be acquired in 15–250 s by applying continuous crystal rotation, and the required electron dose rate can be very low (<0.1 e s−1 Å−2). In this review, we describe the evolution of 3DED data collection techniques and how the recent development of continuous rotation electron diffraction techniques improves data quality. We further describe the structure elucidation of MOFs using 3DED techniques, showing examples of using both low- and high-resolution 3DED data. With an improved data quality, 3DED can achieve a high accuracy, and reveal more structural details of MOFs. Because the physical and chemical properties of MOFs are closely associated with their crystal structures, we believe 3DED will only increase its importance in developing MOF materials.

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Long-range ordering or not: magnetic properties modulated by second ligands in flexible three-dimensional metal–organic frameworks

Chemical Communications ◽

10.1039/c0cc00166j ◽

2010 ◽

Vol 46 (29) ◽

pp. 5349 ◽

Cited By ~ 42

Author(s):

Hua Tian ◽

Qin-Xiang Jia ◽

En-Qing Gao ◽

Qing-Lun Wang

Keyword(s):

Magnetic Properties ◽

Long Range ◽

Metal Organic Frameworks ◽

Three Dimensional ◽

Metal Organic ◽

Long Range Ordering

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Four Novel d10 Metal-Organic Frameworks Incorporating Amino-Functionalized Carboxylate Ligands: Synthesis, Structures, and Fluorescence Properties

Frontiers in Chemistry ◽

10.3389/fchem.2021.708314 ◽

2021 ◽

Vol 9 ◽

Author(s):

Wang Xie ◽

Jie Wu ◽

Xiaochun Hang ◽

Honghai Zhang ◽

Kang shen ◽

...

Keyword(s):

Metal Organic Frameworks ◽

Three Dimensional ◽

Fluorescence Properties ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Quenching Effect ◽

D10 Metal ◽

Metal Organic ◽

Point Symbol

By employment of amino-functionalized dicarboxylate ligands to react with d10 metal ions, four novel metal-organic frameworks (MOFs) were obtained with the formula of {[Cd(BCPAB)(μ2-H2O)]}n (1), {[Cd(BDAB)]∙2H2O∙DMF}n (2), {[Zn(BDAB)(BPD)0.5(H2O)]∙2H2O}n (3) and {[Zn(BDAB)(DBPB)0.5(H2O)]∙2H2O}n (4) (H2BCPAB = 2,5-bis(p-carbonylphenyl)-1-aminobenzene; H2BDAB = 1,2-diamino-3,6-bis(4-carboxyphenyl)benzene); BPD = (4,4′-bipyridine); DBPB = (E,E-2,5-dimethoxy-1,4-bis-[2-pyridin-vinyl]-benzene; DMF = N,N-dimethylformamide). Complex 1 is a three-dimensional (3D) framework bearing seh-3,5-Pbca nets with point symbol of {4.62}{4.67.82}. Complex 2 exhibits a 4,4-connected new topology that has never been reported before with point symbol of {42.84}. Complex 3 and 4 are quite similar in structure and both have 3D supramolecular frameworks formed by 6-fold and 8-fold interpenetrated 2D coordination layers. The structures of these complexes were characterized by single crystal X-ray diffraction (SC-XRD), thermal gravimetric analysis (TGA) and powder X-ray diffraction (PXRD) measurements. In addition, the fluorescence properties and the sensing capability of 2–4 were investigated as well and the results indicated that complex 2 could function as sensor for Cu2+ and complex 3 could detect Cu2+ and Ag+via quenching effect.

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High-Throughput Electron Diffraction Reveals a Hidden Novel Metal-Organic Framework for Electrocatalysis

10.26434/chemrxiv.13725817.v2 ◽

2021 ◽

Author(s):

Meng Ge ◽

Yanzhi Wang ◽

Francesco Carraro ◽

Weibin Liang ◽

Morteza Roostaeinia ◽

...

Keyword(s):

Electron Diffraction ◽

High Throughput ◽

Metal Organic Framework ◽

Three Dimensional ◽

Reduction Reaction ◽

New Materials ◽

X Ray Diffraction ◽

Zeolitic Imidazolate Framework ◽

Wide Range ◽

Metal Organic

Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO3-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm-). With a composition of Zn3(mIm)5(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications.

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