scholarly journals Structure determination of the 3×3 superstructure of the (111)-B-surface of InSb by three-dimensional X-ray data

1993 ◽  
Vol 49 (s1) ◽  
pp. c311-c311
Author(s):  
J. Wever ◽  
H. L. Meyerheim ◽  
V. Jahns ◽  
W. Moritz ◽  
H. Schulz
Keyword(s):  
Structure Determination ◽  
Three Dimensional ◽  
X Ray

Structure determination of a partially ordered layered silicate material with an NMR crystallography approach

2017 ◽  
Vol 73 (3) ◽  
pp. 184-190 ◽  
Author(s):  
Darren Henry Brouwer ◽  
Sylvian Cadars ◽  
Kathryn Hotke ◽  
Jared Van Huizen ◽  
Nicholas Van Huizen
Keyword(s):  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Three Dimensional ◽  
Layered Silicate ◽  
Silicate Layer ◽  
Silicate Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Crystallography

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.

Structure determination of three-dimensional hafnium silicide nano structures on Si(100) by means of X-ray photoelectron diffraction

2008 ◽  
Vol 602 (24) ◽  
pp. 3647-3653 ◽  
Author(s):  
C.R. Flüchter ◽  
A. de Siervo ◽  
D. Weier ◽  
M. Schürmann ◽  
A. Beimborn ◽  
...  
Keyword(s):  
Structure Determination ◽  
Three Dimensional ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Nano Structures

Single Crystal X-Ray Structural Determination: A Powerful Technique for Natural Products Research and Drug Discovery

2012 ◽  
Vol 545 ◽  
pp. 3-15
Author(s):  
Hoong Kun Fun ◽  
Suchada Chantrapromma ◽  
Nawong Boonnak
Keyword(s):  
Natural Products ◽  
Drug Discovery ◽  
Single Crystal ◽  
Natural Product ◽  
Structure Determination ◽  
Three Dimensional ◽  
X Ray ◽  
Powerful Technique ◽  
Determination Of Absolute Configuration

Drug discovery from natural products resources have been extensively studied. The most important step in the discovery process is the identification of compounds with interesting biological activity. Single crystal X-ray structure determination is a powerful technique for natural products research and drug discovery in which the detailed three-dimensional structures that emerge can be co-related to the activities of these structures. This article shall present (i) co-crystal structures, (ii) determination of absolute configuration and (iii) the ability to distinguish between whether a natural product compound is a natural product or a natural product artifact. All these three properties are unique to the technique of single crystal X-ray structure determination.

Reaktion von 1.4-Dienen mit Metallkomplexen, I Darstellung und Röntgenstrukturanalyse eines π-enyl-Komplexes der Zusammensetzung (C8H13PdCl)2/ Reaction of 1,4-Dienes with Metal Complexes, I Synthesis and X-ray Structure Determination of a π-enyl Complex of Composition (C8H18PdCl)2

1976 ◽  
Vol 31 (4) ◽  
pp. 455-462 ◽  
Author(s):  
Peter Feldhaus ◽  
Richard Ratka ◽  
Hermann Schmid ◽  
Manfred L. Ziegler
Keyword(s):  
Metal Complexes ◽  
Structure Determination ◽  
Three Dimensional ◽  
Fourier Methods ◽  
X Ray ◽  
H Nmr ◽  
Nmr Data ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

Reaction of (C6H5CN)2PdCl2 and 1,3-dimethylenecyclohexane led to an exocyclic π-enyl complex of formula (C8H13PdCl)2-bis(η3-2-methylene-6-methylcyclohexyl)(di-µ-chloro)-dipalladium. IR and 1H NMR data are in agreement with this formulation.The compound is monoclinic, with unit cell dimensions α = 499.97 ± 0.08, b =1342.26 ± 0.19, c =1379.60 ± 0.20 pm, β = 99.43 ± 0.02°, space group C5h2-P21/C, Ζ = 2, dX-ray = 1.83 g/cm3.The structure was determined from three-dimensional X-ray data by Patterson and Fourier methods. Least squares refinement by use of 1045 independent reflections has reached R1 = 5.6%.

scholarly journals Redetermination of theγ-form of tellurium dioxide

IUCrData ◽  
2017 ◽  
Vol 2 (12) ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Determination ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Accuracy And Precision ◽  
Anisotropic Displacement Parameters ◽  
Absolute Structure

The crystal structure of γ-TeO2was redetermined on the basis of single-crystal X-ray diffraction data. The previous structure determination of this modification was based on laboratory powder X-ray diffraction data [Champarnaud-Mesjardet al.(2000).J. Phys. Chem. Solids,61, 1499–1507]. The current redetermination revealed all atoms with anisotropic displacement parameters, accompanied with a much higher accuracy and precision in terms of bond lengths and angles, and the determination of the absolute structure. The crystal structure consists of TeO4bisphenoids that combine through corner-sharing of all their oxygen atoms into a three-dimensional framework.

Use of zone correction plates and other techniques for structure determination of aperiodic objects at atomic resolution using a conventional electron microscope

1971 ◽  
Vol 261 (837) ◽  
pp. 71-94 ◽  
Keyword(s):  
Electron Microscopy ◽  
Structure Determination ◽  
Spherical Aberration ◽  
Three Dimensional ◽  
Atomic Level ◽  
X Ray ◽  
Image Differencing ◽  
Severe Difficulty ◽  
Significant Structure

Electron microscopy using microscopes with conventional magnetic lenses is restricted in resolution by spherical aberration. The ‘zonal correction principle’ allows this limit to be overcome. Its use in image reconstruction schemes allows separation of the influence of defocusing, astigmatism, etc., from the physically significant structure. The use of three-dimensional methods of image differencing is necessary in order to get interpretable results in the study of the not ‘infinitely thin’ objects in electron microscopy at atomic level. The use of redundancy principles (similar to X -ray structure determination) is discussed and demonstrated. The most severe difficulty, especially in electron microscopy of organic specimens, is radiation damage.

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