The Determination of the Crystal Structure of Anhydrous Theophylline by X-ray Powder Diffraction with a Systematic Search Algorithm, Lattice Energy Calculations, and13C and15N Solid-State NMR:  A Question of Polymorphism in a Given Unit Cell

2001 ◽  
Vol 105 (24) ◽  
pp. 5818-5826 ◽  
Author(s):  
Elaine D. L. Smith ◽  
Robert B. Hammond ◽  
Matthew J. Jones ◽  
Kevin J. Roberts ◽  
John B. O. Mitchell ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Search Algorithm ◽  
Lattice Energy ◽  
Energy Calculations ◽  
X Ray ◽  
Anhydrous Theophylline

Nimustine hydrochloride: the first crystal structure determination of a 2-chloroethyl-N-nitrosourea hydrochloride derivative by X-ray powder diffraction and solid-state NMR

2012 ◽  
Vol 68 (3) ◽  
pp. o144-o148 ◽  
Author(s):  
Sándor L. Bekö ◽  
David Urmann ◽  
Andrea Lakatos ◽  
Clemens Glaubitz ◽  
Martin U. Schmidt
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Pyrimidine Ring ◽  
Powder Diffraction Data ◽  
Cytostatic Agent ◽  
X Ray ◽  
Nimustine Hydrochloride

Nimustine hydrochloride [systematic name: 4-amino-5-({[N-(2-chloroethyl)-N-nitrosocarbamoyl]amino}methyl)-2-methylpyrimidin-1-ium chloride], C9H14ClN6O2+·Cl−, is a prodrug of CENU (chloroethylnitrosourea) and is used as a cytostatic agent in cancer therapy. Its crystal structure was determined from laboratory X-ray powder diffraction data. The protonation at an N atom of the pyrimidine ring was established by solid-state NMR spectroscopy.

scholarly journals Crystal structure and tautomerism of Pigment Yellow 138 determined by X-ray powder diffraction and solid-state NMR

2016 ◽  
Vol 131 ◽  
pp. 364-372 ◽  
Author(s):  
Silke D. Gumbert ◽  
Meike Körbitzer ◽  
Edith Alig ◽  
Martin U. Schmidt ◽  
Michele R. Chierotti ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
X Ray

Ab initio structure determination of 3,4-diaminopyridin-1-ium dihydrogen phosphate

2011 ◽  
Vol 26 (4) ◽  
pp. 321-325 ◽  
Author(s):  
A. Le Bail ◽  
L’. Smrčok
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Energy Minimization ◽  
Dihydrogen Phosphate ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Ab Initio Structure

The structure of 3,4-diaminopyridin-1-ium dihydrogen phosphate, [C5H3(NH)(NH2)2]+ (H2PO4)−, is solved from conventional X-ray powder diffraction data in direct space (monoclinic unit cell with a = 16.0725(9) Å, b = 7.7301(3) Å, c = 14.6189(9) Å, β = 96.869(1)°, V = 1803.2(2) Å3, Z = 8, and space group I2/c), and optimized by energy minimization in the solid state. In the crystal structure of the title compound, dihydrogenphosphate tetrahedra are linked by strong hydrogen O-H…O bonds forming chains running parallel to the b-axis. Antiparallelly π–π stacked DAP cations form molecular columns in the spaces between the chains. Although the dominant interaction of the molecules with their surroundings is electrostatic, their bonding are further enhanced by N-H…O and C-H…O hydrogen bonds.

A solid-state 133Cs nuclear magnetic resonance and X-ray crystallographic study of cesium complexes with macrocyclic ligands

2000 ◽  
Vol 78 (7) ◽  
pp. 975-985
Author(s):  
Alan Wong ◽  
Simon Sham ◽  
Suning Wang ◽  
Gang Wu
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Chemical Shift ◽  
Solid State Nmr ◽  
Chemical Shifts ◽  
Macrocyclic Ligand ◽  
Chemical Shift Anisotropy ◽  
Macrocyclic Ligands ◽  
X Ray

We report solid-state NMR determination of the 133Cs chemical shift anisotropy (CSA) for a series of cesium complexes with macrocyclic ligands. It was found that the isotropic 133Cs chemical shifts are related to the number of oxygen atoms to which the Cs+ ion is coordinated. The 133Cs chemical shifts were found to correlate with average Cs-O distances. We also attempt to use the established correlation to deduce Cs+ coordination environment for compounds with unknown structures. We also report the X-ray determination of the crystal structure for Cs(DB18C6)2SCN•1/2CH3OH•1/2H2O. The compound crystallizes in monoclinic, a = 14.503(2), b = 15.152(3), c = 39.989(6) Å, β = 90.796(8)°, space group P21/c, Z = 8. There are two independent molecules in the asymmetric unit cell where each of the two Cs+ ions is coordinated to two DB18C6 ligand molecules forming a sandwich-type structure.Key words: solid state NMR, alkali metal, 133Cs chemical shift, macrocyclic ligand, crystal structure.

scholarly journals Synthesis, characterization and modeling of self-assembled porphyrin nanorods

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1346-1354 ◽  
Author(s):  
Danielle Laurencin ◽  
Pascal G. Yot ◽  
Christel Gervais ◽  
Yannick Guari ◽  
Sébastien Clément ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Molecular Level ◽  
Ion Association ◽  
Free Base ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Porphyrin nanorods were prepared by ion-association between free-base meso 5,10,15,20-tetrakis-(4-[Formula: see text]-methylpyridinium)porphyrin cations and tetraphenylborate anions. The nanorods have variable lengths (up to a few micrometers long) and diameters ([Formula: see text]50–500 nm). Their structure at the molecular level was elucidated by combining multinuclear solid state NMR spectroscopy, synchrotron X-ray powder diffraction and DFT calculations.

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.

SYNTHESIS, MORPHOLOGY AND STRUCTURAL PROPERTIES OF (GD,ND)SR2RUCU2O8 SAMPLES

2003 ◽  
Vol 17 (04n06) ◽  
pp. 899-904 ◽  
Author(s):  
A. VECCHIONE ◽  
M. GOMBOS ◽  
C. TEDESCO ◽  
A. IMMIRZI ◽  
L. MARCHESE ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
X Ray ◽  
Structure And Morphology ◽  
Polycrystalline Powder ◽  
Scanning Electron

NdSr 2 RuCu 2 O x material has been prepared as polycrystalline powder by solid state reaction. The compound has been investigated by synchrotron x-ray powder diffraction and scanning electron microscopy. The experimental results show that the average crystal structure is a disordered cubic perovskite with Nd and Sr cations occupying the same site and the same substitution is found for Cu and Ru atoms. A comparison between the crystal structure and morphology of this compound and the superconducting tetragonal GdSr 2 RuCu 2 O 8 is also discussed.

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