Correction to Precise Analysis of Thermal Volume Expansion of Crystal Lattice for Fully Aromatic Crystalline Polyimides by X-ray Diffraction Method: Relationship between Molecular Structure and Linear/Volumetric Thermal Expansion

2017 ◽  
Vol 50 (6) ◽  
pp. 2599-2600 ◽  
Author(s):  
Ryohei Ishige ◽  
Toshiaki Masuda ◽  
Yukiko Kozaki ◽  
Eisuke Fujiwara ◽  
Tomohiro Okada ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Thermal Expansion ◽  
Crystal Lattice ◽  
Volume Expansion ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Volumetric Thermal Expansion ◽  
Precise Analysis ◽  
Thermal Volume Expansion

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

Polymorphic transformations and thermal expansion of some modifications in Ag1.5Cu0.5Se and Ag0.4Cu1.6Se

2019 ◽  
Vol 33 (23) ◽  
pp. 1950271 ◽  
Author(s):  
Y. I. Aliyev ◽  
Y. G. Asadov ◽  
A. O. Dashdemirov ◽  
R. D. Aliyeva ◽  
T. G. Naghiyev ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Polymorphic Transformations ◽  
X Ray

The Ag[Formula: see text]Cu[Formula: see text]Se and Ag[Formula: see text]Cu[Formula: see text]Se compounds have been synthesized and grown as single crystals. High-temperature X-ray diffraction method was used to study polymorphic transformations. It is shown that the Ag[Formula: see text]Cu[Formula: see text]Se crystals of high-temperature FCC modification are decomposed into Ag2Se and AgCuSe when the temperature decreases below T = 488 K and Ag[Formula: see text]Cu[Formula: see text]Se is decomposed into Cu2Se and AgCuSe when the temperature decreases below T = 540 K. Transformations in both compounds are reversible. Crystalline parameters are obtained and the temperature dependence of the lattice parameters for each phase is built.

Crystal Structure of ζ2' Martensite in Au-49.5at%Cd Alloy

1991 ◽  
Vol 246 ◽  
Author(s):  
Yutaka Emura ◽  
Takuya Ohba ◽  
Kazuhiro Otsuka
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Least Squares ◽  
Least Squares Method ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Lattice Constants

AbstractCrystal structure of the ζ2' martensite in a Au-49.5at%Cd ally has been analyzed by the single crystal x-ray diffraction method. The crystal lattice was trigonal and the lattice constants were a:0.8095(3) and c=o.57940(6) nm. There were 18 atoms in a unit cell. The space group was P3, which was different from that previously determined by Vatanayon and Hehemann. The structure was refined by the full matrix least squares method to a final R factor of 7.8% and a weighted R factor of 4.1%.

(E)-1-(9-Anthryl)-2-(10-methyl-9-anthryl)ethene: Molecular Structure and Spectroscopic Properties

1985 ◽  
Vol 38 (5) ◽  
pp. 809 ◽  
Author(s):  
H Becker ◽  
L Hansen ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Crystal Lattice ◽  
Molecular Geometry ◽  
Spectroscopic Properties ◽  
Interplanar Distance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Triphenylphosphonium Bromide

(E)-1-(9-Anthryl)-2-(10-methyl-9-anthryl) ethelle has been synthesized from 10-methyl-9-anthraldehyde and (9-anthrylmethyl) triphenylphosphonium bromide, and its crystal structure has been determined by X-ray diffraction. Its molecular geometry was found to be such as to have the planes of the two anthracene moieties form an angle of 70.8°, the plane of the ethene bond bring twisted out of the planes of the anthracenes by an angle of about 55°. The intermolecular arrangement of parallel adjacent molecules in the crystal lattice is characterized by shifts about the short and long axes of the anthracenes. The excimer-like crystal fluorescence is attributed to the interplanar distance of 3.5 Ǻ between anthracene π- systems in parallel adjacent molecules. Crystals are triclinic, Pī , a 12.95(1), b 9.316(6), c 9.098(9) Ǻ, α 86.17(7), β 72.26(7), γ 74.61(6)°,Z 2; R was 0.054 for 1059 independent 'observed' reflections.

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