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

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.

Author(s):  
L. S. Ivashkevich ◽  
A. S. Lyakhov ◽  
A. F. Selevich ◽  
A. I. Lesnikovich

AbstractThe crystal structure of In


2012 ◽  
Vol 68 (3) ◽  
pp. o144-o148 ◽  
Author(s):  
Sándor L. Bekö ◽  
David Urmann ◽  
Andrea Lakatos ◽  
Clemens Glaubitz ◽  
Martin U. Schmidt

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.


Author(s):  
H. Gies ◽  
J. Rius

AbstractThe ab-initio solution of the crystal structure of the zeolite material RUB-10 from X-ray powder diffraction data at 2 Å resolution is presented. Microcrystallinity and poor crystallinity are inherent properties of this material that could not be overcome by optimizing the synthesis conditions. RUB-10 is monoclinic with space group


2018 ◽  
Vol 33 (4) ◽  
pp. 298-302
Author(s):  
Austin M. Wheatley ◽  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of bretylium tosylate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Bretylium tosylate crystallizes in space group C2/c (#15) with a = 32.6238(4), b = 12.40353(14), c = 9.93864(12) Å, β = 101.4676(10), V = 3941.39(5) Å3, and Z = 8. The sample exhibited visible decomposition in the X-ray beam. The unusual displacement ellipsoid of the Br atom probably indicates that the decomposition in the beam involves the Br atom. The crystal structure can be viewed as layered parallel to the bc plane. The layers are double, the center consisting of the cation/anion polar interactions and the outer surface of the double layers consists of hydrocarbon interactions. In the absence of normal hydrogen bond donors, the only hydrogen bonds in the bretylium tosylate structure are C–H…O hydrogen bonds. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.


2009 ◽  
Vol 24 (3) ◽  
pp. 185-190 ◽  
Author(s):  
A. Le Bail

θ-KAlF4 is a new nanosized potassium tetrafluoroaluminate metastable polymorph (13×18×55 nm3). The crystal structure is solved ab initio from X-ray powder diffraction data in direct space [orthorhombic unit cell with a=8.3242(3) Å, b=7.2502(3) Å, c=11.8875(4) Å, V=717.44(5) Å3, Z=8, and space group Pnma]. This new structure type, unique in the whole AIMIIIF4 family, is related to the fluorite structure and consists of AlF6 octahedra linked via a common edge forming a bioctahedral motif which is trans-connected through the corner-shared fluorine, resulting in the formation of infinite ladderlike double file of octahedra ([Al2F8]2−)n running along the b axis.


2016 ◽  
Vol 31 (1) ◽  
pp. 59-62
Author(s):  
Martin Etter ◽  
Maximilian J. Krautloher ◽  
Nakheon Sung ◽  
Joel Bertinshaw ◽  
Bumjoon Kim ◽  
...  

A new non-stoichiometric calcium ruthenate [Ca4−xRuO6−x with x = 1.17(1)] was synthesized by the flux growth method and characterized by the X-ray powder diffraction. The crystal structure is isostructural to the K4CdCl6 type with space group R$\bar 3$c. Unit-cell parameters are a = 9.2881(1), c = 11.1634(2) Å, V = 834.03(3) Å3, and Z = 6.


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