scholarly journals Three-dimensional electron diffraction for porous crystalline materials: structural determination and beyond

2021 ◽  
Author(s):  
Zhehao Huang ◽  
Tom Willhammar ◽  
Xiaodong Zou

Three-dimensional electron diffraction is a powerful tool for accurate structure determination of zeolite, MOF, and COF crystals that are too small for X-ray diffraction. By revealing the structural details, the properties of the materials can be understood, and new materials and applications can be designed.

2014 ◽  
Vol 47 (1) ◽  
pp. 215-221 ◽  
Author(s):  
Devinder Singh ◽  
Yifeng Yun ◽  
Wei Wan ◽  
Benjamin Grushko ◽  
Xiaodong Zou ◽  
...  

Electron diffraction is a complementary technique to single-crystal X-ray diffraction and powder X-ray diffraction for structure solution of unknown crystals. Crystals too small to be studied by single-crystal X-ray diffraction or too complex to be solved by powder X-ray diffraction can be studied by electron diffraction. The main drawbacks of electron diffraction have been the difficulties in collecting complete three-dimensional electron diffraction data by conventional electron diffraction methods and the very time-consuming data collection. In addition, the intensities of electron diffraction suffer from dynamical scattering. Recently, a new electron diffraction method, rotation electron diffraction (RED), was developed, which can overcome the drawbacks and reduce dynamical effects. A complete three-dimensional electron diffraction data set can be collected from a sub-micrometre-sized single crystal in less than 2 h. Here the RED method is applied forab initiostructure determination of an unknown complex intermetallic phase, the pseudo-decagonal (PD) quasicrystal approximant Al37.0(Co,Ni)15.5, denoted as PD2. RED shows that the crystal is F-centered, witha= 46.4,b= 64.6,c= 8.2 Å. However, as with other approximants in the PD series, the reflections with oddlindices are much weaker than those withleven, so it was decided to first solve the PD2 structure in the smaller, primitive unit cell. The basic structure of PD2 with unit-cell parametersa= 23.2,b= 32.3,c= 4.1 Å and space groupPnmmhas been solved in the present study. The structure withc= 8.2 Å will be taken up in the near future. The basic structure contains 55 unique atoms (17 Co/Ni and 38 Al) and is one of the most complex structures solved by electron diffraction. PD2 is built of characteristic 2 nm wheel clusters with fivefold rotational symmetry, which agrees with results from high-resolution electron microscopy images. Simulated electron diffraction patterns for the structure model are in good agreement with the experimental electron diffraction patterns obtained by RED.


IUCrJ ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 267-282 ◽  
Author(s):  
Yifeng Yun ◽  
Xiaodong Zou ◽  
Sven Hovmöller ◽  
Wei Wan

Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED) data collection, namely automated diffraction tomography (ADT) and rotation electron diffraction (RED), have been developed. Compared with X-ray diffraction (XRD) and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD) provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni–Se–O–Cl crystals, zeolites, germanates, metal–organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three-dimensional ED methods will become crucially important in the near future.


Author(s):  
Tatiana E. Gorelik ◽  
Jacco van de Streek ◽  
Herbert Meier ◽  
Lars Andernach ◽  
Till Opatz

The solid-state structure of star-shaped 2,4,6-tris{(E)-2-[4-(dimethylamino)-phenyl]ethenyl}-1,3,5-triazine is determined from a powder sample by exploiting the respective strengths of single-crystal three-dimensional electron diffraction and powder X-ray diffraction data. The unit-cell parameters were determined from single crystal electron diffraction data. Using this information, the powder X-ray diffraction data were indexed, and the crystal structure was determined from the powder diffraction profile. The compound crystallizes in a noncentrosymmetric space group,P212121. The molecular conformation in the crystal structure was used to calculate the molecular dipole moment of 3.22 Debye, which enables the material to show nonlinear optical effects.


2016 ◽  
Vol 3 (11) ◽  
pp. 1351-1362 ◽  
Author(s):  
Zhengyang Zhou ◽  
Lukáš Palatinus ◽  
Junliang Sun

The combination of PXRD and ED is applied to determine modulated structures which resist solution by more conventional methods.


2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  

<p>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-CO<sub>3</sub>-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<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(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. </p>


2006 ◽  
Vol 59 (9) ◽  
pp. 647 ◽  
Author(s):  
Yong-Tao Wang ◽  
Gui-Mei Tang ◽  
Da-Wei Qin

Three new inorganic–organic coordination polymers based on a versatile linking unit 2-(1H-imidazole-1-yl)acetate (Hima) and divalent Mn(ii), Ni(ii), and Cu(ii) ions, exhibiting two kinds of two dimensionalities with different topological structures, have been prepared in water medium and structurally characterized by single-crystal X-ray diffraction analysis. Reaction of MnCl2·4H2O and Ni(NO3)2·6H2O with Hima yielded neutral two-dimensional (2D) coordination polymers [M(ima)2]n, M = Mn(ii) 1, and Ni(ii) 2 with isostructural 2D coordination polymers possessing (3,6) topology structures, which further stack into three-dimensional (3D) supramolecular networks through C–H···O weak interactions. However, when Cu(NO3)2·4H2O was used, a neutral 2D coordination polymer [Cu(ima)2]n 3 consisting of rhombus units was generated, which showed a 3D supramolecular network through C–H···O weak interactions. Among these polymers, the building block ima anion exhibits different coordination modes. These results indicate that the versatile nature of this flexible ligand, together with the coordination preferences of the metal ions, plays a critical role in construction of these novel coordination polymers. Spectral and thermal properties of these new materials have also been investigated.


2017 ◽  
Vol 4 (10) ◽  
pp. 1654-1659 ◽  
Author(s):  
Yilin Wang ◽  
Yunchen Wang ◽  
Jie Su ◽  
Xiaowei Song ◽  
Wei Wan ◽  
...  

Structure determination of silicogermanate with sti layers pillared by D4R/Ge7 units by rotation electron diffraction and powder X-ray diffraction.


2017 ◽  
Vol 73 (3) ◽  
pp. 184-190 ◽  
Author(s):  
Darren Henry Brouwer ◽  
Sylvian Cadars ◽  
Kathryn Hotke ◽  
Jared Van Huizen ◽  
Nicholas Van Huizen

Structure determination of layered materials can present challenges for conventional diffraction methods due to the fact that such materials often lack full three-dimensional periodicity since adjacent layers may not stack in an orderly and regular fashion. In such cases, NMR crystallography strategies involving a combination of solid-state NMR spectroscopy, powder X-ray diffraction, and computational chemistry methods can often reveal structural details that cannot be acquired from diffraction alone. We present here the structure determination of a surfactant-templated layered silicate material that lacks full three-dimensional crystallinity using such an NMR crystallography approach. Through a combination of powder X-ray diffraction and advanced 29Si solid-state NMR spectroscopy, it is revealed that the structure of the silicate layer of this layered silicate material templated with cetyltrimethylammonium surfactant cations is isostructural with the silicate layer of a previously reported material referred to as ilerite, octosilicate, or RUB-18. High-field 1H NMR spectroscopy reveals differences between the materials in terms of the ordering of silanol groups on the surfaces of the layers, as well as the contents of the inter-layer space.


Nano Letters ◽  
2010 ◽  
Vol 10 (5) ◽  
pp. 1922-1926 ◽  
Author(s):  
Yukio Takahashi ◽  
Nobuyuki Zettsu ◽  
Yoshinori Nishino ◽  
Ryosuke Tsutsumi ◽  
Eiichiro Matsubara ◽  
...  

Author(s):  
Jacqueline M. Cole

This review describes the development and application of a new crystallographic technique that is starting to enable the three-dimensional structural determination of molecules in their photo-activated states. So called `photocrystallography' has wide applicability, particularly in the currently exciting area of photonics, and a discussion of this applied potential is put into context in this article. Studies are classified into four groups: photo-structural changes that are (i) irreversible; (ii) long-lived but reversible under certain conditions; (iii) transient with photo-active lifetimes of the order of microseconds; (iv) very short lived, existing at the nanosecond or even picosecond level. As photo-structural changes relative to the `ground state' can be subtle, this article necessarily concentrates on small-molecule single-crystal X-ray diffraction given that high atomic resolution is possible. That said, where it is pertinent, references are also made to related major advances in photo-induced macromolecular crystallography. The review concludes with an outlook on this new research area, including the future possibility of studying even more ephemeral, femtosecond-lived, photo-active species.


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