Crystal structure of propylthiouracil determined using high-resolution synchrotron X-ray powder diffraction

CrystEngComm ◽  
2011 ◽  
Vol 13 (17) ◽  
pp. 5474 ◽  
Author(s):  
Fabio Furlan Ferreira ◽  
Antonio Carlos Trindade ◽  
Selma Gutierrez Antonio ◽  
Carlos de Oliveira Paiva-Santos
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Powder Diffraction ◽  
X Ray

Crystal structure study of selected xanthine derivatives

2010 ◽  
Vol 43 (1) ◽  
pp. 163-167 ◽  
Author(s):  
W. Lasocha ◽  
B. Gaweł ◽  
A. Rafalska-Lasocha ◽  
M. Pawłowski ◽  
P. Talik ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Powder Diffraction ◽  
Structure Study ◽  
Asymmetric Unit ◽  
Pharmaceutical Samples ◽  
X Ray ◽  
Xanthine Derivatives ◽  
Structure Solution ◽  
Theophylline Derivatives

The crystal structures of two compounds belonging to a group of theophylline derivatives have been solved by X-ray powder diffraction methods. Despite the fact that these compounds seemed to be rather simple (23 atoms in an asymmetric unit), the preferred orientation and dominant zone problems created very serious obstacles in the investigations, even for the most modern powder diffraction methods. The crystal structure of the first compound, 8-phenylazoxanthine, C14H14N6O2, was finally solved from laboratory diffractometer data, while in the case of the second compound, 8-(3-bromobenzylidene)xanthine, C15H14N5O2Br, it was not possible to reliably index its diffraction pattern until data had been collected at the high-resolution powder diffractometer ID31 at the ESRF Grenoble. The serious problems encountered during anab initiocrystal structure solution from powder data of these pharmaceutical samples are described and discussed.

Disordered crystal structure of pentamethylcyclopentadienylsodium as seen by high-resolution X-ray powder diffraction

2001 ◽  
Vol 57 (5) ◽  
pp. 673-679 ◽  
Author(s):  
Consiglia Tedesco ◽  
Robert E. Dinnebier ◽  
Falk Olbrich ◽  
Sander van Smaalen
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Lattice Parameters ◽  
Space Group ◽  
X Ray ◽  
Disordered Crystal

The crystal structure of pentamethylcyclopentadienylsodium, [NaC10H15] (NaCp*), has been determined from high-resolution X-ray powder diffraction. The compound crystallizes in space group Cmcm with lattice parameters a = 4.61030 (3), b = 16.4621 (3), c = 14.6751 (2) Å, V = 1113.77 (4) Å3 (Z = 4). NaCp* forms polymeric multidecker chains along the a axis. The Rietveld refinement (Rp = 0.050 and RF = 0.163) shows that the Cp* moieties occupy, with disorder, two different orientations rotated away from the eclipsed conformation by ±13.8°.

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.

Crystal structure determination of mebendazole form A using high‐resolution synchrotron x‐ray powder diffraction data

2010 ◽  
Vol 99 (4) ◽  
pp. 1734-1744 ◽  
Author(s):  
Fabio Furlan Ferreira ◽  
Selma Gutierrez Antonio ◽  
Paulo César Pires Rosa ◽  
Carlos de Oliveira Paiva‐Santos
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
Powder Diffraction Data ◽  
X Ray

scholarly journals Sideroxylin from Miconia Ioneura: Monohydrate Crystal Structure from High Resolution X-Ray Powder Diffraction

2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300
Author(s):  
Silvina Pagola ◽  
María I. Tracanna ◽  
Sara M. Amani ◽  
Ana M. González ◽  
Ana B. Raschi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Simulated Annealing ◽  
Thermogravimetric Analysis ◽  
High Resolution ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Simulated Annealing Algorithm ◽  
Ethyl Acetate Extract ◽  
X Ray ◽  
Annealing Algorithm

High resolution X-ray powder diffraction has been used to obtain the crystal structure of sideroxylin ( 4H-1-Benzopyran-4-one,5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-6,8-dimethyl) monohydrate, (C18H16O5).H2O, isolated from the bioactive ethyl acetate extract of Miconia ioneura Griseb (Melastomataceae) leaves. The crystal structure was determined using direct space methodology based on the simulated annealing algorithm. Thermogravimetric analysis shows that the material dehydrates while heated from room temperature to ~150°C.

Crystal Structure of the [(C5H4BMe2)2Fe]-4,4′-bipyridine Polymer from High Resolution X-Ray Powder Diffraction

2000 ◽  
Vol 626 (6) ◽  
pp. 1400-1405 ◽  
Author(s):  
Robert E. Dinnebier ◽  
Matthias Wagner ◽  
Frank Peters ◽  
Kenneth Shankland ◽  
William I. F. David
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Powder Diffraction ◽  
X Ray
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