Powder Diffraction Data of Three Tetrahydropyridinyl Oxime Cognition Activators of Formula C8H15N2O+Cl−

1992 ◽  
Vol 7 (3) ◽  
pp. 170-173 ◽  
Author(s):  
G. Bandoli ◽  
M. Nicolini ◽  
A. Ongaro
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Single Crystal Structure ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Data Comparison ◽  
Structure Determinations

AbstractIndexed X-ray powder diffraction data are reported for three tetrahydropyridinyl oxime cognition activators. For these drugs of formula C8H15N2O+Cl− powder diffraction data calculated from single crystal structure determinations are also presented and compared to the experimentally observed powder diffraction data. Comparison of experimental and calculated powder patterns assures that single crystals are good representatives of the commercial powdered samples.

Powder diffraction data of two tricydic diazonia diiodide salts used in silver iodide solid electrolytes

1993 ◽  
Vol 8 (3) ◽  
pp. 175-179
Author(s):  
J. Estienne ◽  
O. Cerclier ◽  
J. J. Rosenberg
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Silver Iodide ◽  
Solid Electrolytes ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
Organic Salts ◽  
X Ray ◽  
Structure Determinations

Indexed X-ray powder diffraction data are reported for two organic salts with carbon rings having two quaternary nitrogens: diazonia-6,9 dispiro [5.2.5.2] hexadecane and diazonia-6,9 dispiro [5.2.5.3] heptadecane diiodides. For these compounds, which give solid electrolytes when associated with AgI, powder diffraction diagrams calculated by the Rietveld method from single crystal structure determinations are presented and are compared to the experimental diffraction data.

Combined Rietveld and stereochemical restraint refinement of a protein crystal structure

1999 ◽  
Vol 32 (6) ◽  
pp. 1084-1089 ◽  
Author(s):  
R. B. Von Dreele
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Tertiary Structure ◽  
Protein Crystal ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Protein Crystal Structure

By combining high-resolution X-ray powder diffraction data and stereochemical restraints, Rietveld refinement of protein crystal structures has been shown to be feasible. A refinement of the 1261-atom protein metmyoglobin was achieved by combining 5338 stereochemical restraints with a 4648-step (dmin= 3.3 Å) powder diffraction pattern to give the residualsRwp= 2.32%,Rp= 1.66%,R(F2) = 3.10%. The resulting tertiary structure of the protein is essentially identical to that obtained from previous single-crystal studies.

scholarly journals Ab initio and DFT study on Cu (II) complex salicylate derivative

2014 ◽  
Vol 70 (a1) ◽  
pp. C1442-C1442
Author(s):  
Karthikeyan Natarajan ◽  
Sathya Duraisamy ◽  
Sivakumar Kandasamy
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray

X -ray diffraction becomes a routine process these decades for determining crystal structure of the materials. Most of the crystal structures solved nowadays is based on single crystal X-ray diffraction because it solves the crystal and molecular structures from small molecules to macro molecules without much human intervention. However it is difficult to grow single crystals of sufficient size and quality for conventional single-crystal X-ray diffraction studies. In such cases it becomes essential that structural information can be determined from powder diffraction data. With the recent developments in the direct-space approaches for structure solution, ab initio crystal structure analysis of molecular solids can be accomplished from X-ray powder diffraction data. It should be recalled that crystal structure determination from laboratory X-ray powder diffraction data is a far more difficult task than that of its single-crystal counterpart, particularly when the molecule possesses considerable flexibility or there are multiple molecules in the asymmetric unit. Salicylic acid and its derivatives used as an anti-inflammatory drug are known for its numerous medicinal applications. In our study, we synthesized mononuclear copper (II) complex of salicylate derivative. The structural characterization of the prepared compound was carried out using powder X-ray diffraction studies. Crystal structure of the compound has been solved by direct-space approach and refined by a combination of Rietveld method using TOPAS Academic V4.1. Density Functional Theory (DFT) calculations have to be carried in the solid state for the compound using GaussianW9.0 in the frame work of a generalized-gradient approximation (GGA). The geometry optimization was to be performed using B3LYP density functional theory. The atomic coordinates were taken from the final X-ray refinement cycle.

Structure Re-determination of LASSBio-294 – a cardioactive compound of the N-acylhydrazone class – using X-ray powder diffraction data

2013 ◽  
Vol 28 (S2) ◽  
pp. S491-S509 ◽  
Author(s):  
Fanny N. Costa ◽  
Fabio Furlan Ferreira ◽  
Tiago F. da Silva ◽  
Eliezer J. Barreiro ◽  
Lídia M. Lima ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Goodness Of Fit ◽  
Rietveld Method ◽  
Therapeutic Interventions ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Cell Parameters

Many N-acylhydrazone derivatives synthetized in LASSBio® cannot be prepared as single crystals of sufficient size and/or quality for structure determination to be carried out using single crystal X-ray diffraction techniques. This article highlights the opportunity for determining crystal structures of this class of compounds directly from powder diffraction data. For this task, the crystal structure of LASSBio-294 was re-determined by means of conventional X-ray powder diffraction data and so, compared with the crystal structure already determined for single crystal data. LASSBio-294 is a cardioactive compound of the N-acylhydrazone class, which can become part of the therapeutic interventions designed to decrease exertional fatigue, and, consequently, improve the quality of life of patients suffering from chronic heart failure. Its final crystal structure was refined by means of the Rietveld method (Rietveld, 1967; 1969). This drug crystallizes in a monoclinic (P21/c) space group, with unit cell parameters a = 11.3413(3) Å, b = 12.3573(4) Å, c = 9.0158(3) Å, β = 89.821(2)°, V = 1263.55(7) Å3, Z = 4, Ź = 1 and ρcalc = 1.4419(1) g cm−3. The goodness-of-fit indicator and R-factors were, respectively: χ2 = 1.203, RBragg = 0.696%, Rwp = 5.59%, Rexp = 4.65% and Rp = 4.18%. The molecules in LASSBio-294 are H-bonded along the c-axis involving the atoms N(3)–H(8)···O(4).

Metastable β-phase of benzophenone: independent structure determinations via X-ray powder diffraction and single crystal studies

2000 ◽  
Vol 56 (3) ◽  
pp. 486-496 ◽  
Author(s):  
Hartmut Kutzke ◽  
Helmut Klapper ◽  
Robert B. Hammond ◽  
Kevin J. Roberts
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Metastable Phase ◽  
Search Space ◽  
Powder Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Β Phase ◽  
Structure Determinations

Benzophenone was the first organic molecular material to be identified as polymorphic. It is well known that benzophenone crystallizes in a stable orthorhombic α-form (m.p. 321 K) with space group P212121 and a = 10.28, b = 12.12, c = 7.99 Å, [Girdwood (1998). Ph.D. thesis. Strathclyde University, Glasgow, Scotland]. Here we report two separate structure determinations of the metastable β-form (m.p. 297–299 K). Crystalline material of the metastable polymorph was obtained from a melt supercooled to ∼243 K. The structure was determined from X-ray powder diffraction data by employing a novel, computational systematic search procedure to identify trial packing arrangements for subsequent refinement. Unit-cell and space-group information, determined from indexing the powder diffraction data, was used to define the search space. The structure was also determined from single-crystal diffraction data at room temperature and at 223 K. The metastable phase is monoclinic with space group C2/c and a = 16.22, b = 8.15, c = 16.33 Å, β = 112.91° (at 223 K). The structures derived from the individual techniques are qualitatively the same. They are compared both with each other and with the stable polymorph and other benzophenone derivatives.

scholarly journals Symmetry reduction due to gallium substitution in the garnet Li6.43(2)Ga0.52(3)La2.67(4)Zr2O12

2016 ◽  
Vol 72 (3) ◽  
pp. 287-289 ◽  
Author(s):  
Lars Robben ◽  
Elena Merzlyakova ◽  
Paul Heitjans ◽  
Thorsten M. Gesing
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
Lanthanum Zirconate ◽  
Cubic Symmetry ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

Single-crystal structure refinements on lithium lanthanum zirconate (LLZO; Li7La3Zr2O12) substituted with gallium were successfully carried out in the cubic symmetry space groupI\overline{4}3d. Gallium was found on two lithium sites as well as on the lanthanum position. Due to the structural distortion of the resulting Li6.43(2)Ga0.52(3)La2.67(4)Zr2O12(Ga–LLZO) single crystals, a reduction of the LLZO cubic garnet symmetry fromIa\overline{3}dtoI\overline{4}3dwas necessary, which could hardly be analysed from X-ray powder diffraction data.

Structure determination of diclofenac in a diclofenac-containing chitosan matrix using conventional X-ray powder diffraction data

2004 ◽  
Vol 37 (2) ◽  
pp. 288-294 ◽  
Author(s):  
Nongnuj Muangsin ◽  
Malee Prajuabsook ◽  
Pitiporn Chimsook ◽  
Nuanphun Chantarasiri ◽  
Krisana Siraleartmukul ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Chitosan Matrix

The structure determination of diclofenac embedded in a diclofenac-containing chitosan matrix using conventional X-ray powder diffraction data is demonstrated. It reveals that sodium diclofenac, the starting material in the preparation of a controlled-release diclofenac-containing chitosan matrix, changes to diclofenac acid in space groupC2/cin the matrix. Simple methods were employed for handling the sample to obtain X-ray powder diffraction data of sufficiently high quality for the determination of the crystal structure of diclofenac embedded in chitosan. These involved grinding and sieving several times through a micro-mesh sieve to obtain a suitable particle size and a uniformly spherical particle shape. A traditional technique for structure solution from X-ray powder diffraction data was applied. The X-ray diffraction intensities were extracted using Le Bail's method. The structure was solved by direct methods from the extracted powder data and refined using the Rietveld method. For comparison, the single-crystal structure of the same drug was also determined. The result shows that the crystal structure solved from conventional X-ray powder diffraction data is in good agreement with that of the single crystal. The deviations of the differences in bond lengths and angles are of the order of 0.030 Å and 0.639°, respectively.

X-ray powder diffraction data for CuFeSe2

1994 ◽  
Vol 9 (2) ◽  
pp. 108-110 ◽  
Author(s):  
J. A. Henaoa ◽  
J. M. Delgado ◽  
M. Quintero
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Structure Data ◽  
Powder Diffraction Data ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Tetragonal System

Recent X-ray single-crystal diffraction studies have shown that CuFeSe2 crystallizes in the tetragonal system with space group P2c [, No. 112], Z = 4, with a =5.530(1) Å and c = 11.049(2) Å, c/a = 1.998. This material had been reported as pseudocubic with a =5.53 Å. The purpose of this paper is to present new X-ray powder diffraction data for CuFeSe2 and to compare the results with those reported for eskebornite, a mineral with ideal chemical composition CuFeSe2, and with those obtained from single-crystal structure data.

X-ray powder diffraction data for RuCI2(TRIPHOS)(DMSO) dichloro [bis(2-diphenylphosphinoethyl) phenylphosphine] [dimethylsulfoxide] ruthenium (II)

1995 ◽  
Vol 10 (3) ◽  
pp. 178-179 ◽  
Author(s):  
Gerzon Delgado ◽  
A. Valentina Rivera ◽  
Trino Suárez ◽  
Bernardo Fontal
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Good Agreement

X-ray powder diffraction data for Dichloro [bis(2-diphenylphosphinoethyl) phenylphosphine] [dimethylsulfoxide] Ruthenium (II) is reported. The powder pattern was obtained using CuKα radiation. The lattice parameters determinated by least-squares refinement for the monoclinic space group P21/c are: a = 21.073(3) Å, b = 11.970(2) Å, c = 16.889(3) Å, and β = 107.72(1)°, with M20 = 10.67 and F30 = 15.4 (0.0145, 134), and are in good agreement with those obtained from the single crystal structure determination. Observed and calculated X-ray powder diffraction data are given for the titled compound.

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