Structure of sodiumpara-hydroxybenzoate, NaO2C–C6H4OH by powder diffraction: application of a phenomenological model of anisotropic peak width

1999 ◽  
Vol 32 (4) ◽  
pp. 761-769 ◽  
Author(s):  
R. E. Dinnebier ◽  
R. Von Dreele ◽  
P. W. Stephens ◽  
S. Jelonek ◽  
J. Sieler

Theab initiostructure solution of sodiumpara-hydroxybenzoate from high-resolution X-ray powder diffraction data is reported. The compound is of interest with respect to understanding the mechanism of Kolbe–Schmitt type reactions. It crystallizes in space groupP21,Z= 2, with unit-cell parametersa= 16.0608 (3),b=  5.38291 (9),c=  3.63834 (6) Å, β =  92.8692 (5)° andV=  314.153 Å3. The compound consists of layers of distorted NaO6prisms perpendicular to theaaxis and phenol rings perpendicular to these layers pointing up and down. The molecular structure is held together by van der Waals forces between the phenyl groups of different layers and additional hydrogen-bridge bonding between the phenolate oxygen atoms. The sample showed powder peak widths which are not a smooth function of diffraction angle; a recently implemented phenomenological model was able to describe this effect sufficiently well to obtain excellent Rietveld fits to the data. The accuracy of modeling the data makes this one of the rare cases where the position of a hydrogen atom could be unambiguously determined by powder techniques.

2010 ◽  
Vol 74 (1) ◽  
pp. 147-157 ◽  
Author(s):  
A. Garavelli ◽  
T. Balić-Žunić ◽  
D. Mitolo ◽  
P. Acquafredda ◽  
E. Leonardsen ◽  
...  

AbstractHeklaite, with the ideal formula KNaSiF6, was found among fumarolic encrustations collected in 1992 on the Hekla volcano, Iceland. Heklaite forms a fine-grained mass of micron- to sub-micron-sized crystals intimately associated with malladrite, hieratite and ralstonite. The mineral is colourless, transparent, non-fluorescent, has a vitreous lustre and a white streak. The calculated density is 2.69 g cm–3. An SEM-EDS quantitative chemical analysis shows the following range of concentrations (wt.%): Na 11.61–12.74 (average 11.98), K 17.02–18.97 (average 18.29), Si 13.48 –14.17 (average 13.91), F 54.88–56.19 (average 55.66). The empirical chemical formula, calculated on the basis of 9 a.p.f.u., is Na1.07K0.96Si1.01F5.97. X-ray powder diffraction indicates that heklaite is orthorhombic, space group Pnma, with the following unit-cell parameters: a = 9.3387(7) Å, b = 5.5032(4) Å, c = 9.7957(8) Å , V = 503.43(7) Å3, Z = 4. The eight strongest reflections in the powder diffraction pattern [d in Å (I/I0) (hkl)] are: 4.33 (53) (102); 4.26 (56) (111); 3.40 (49) (112); 3.37 (47) (202); 3.34 (100) (211); 2.251 (27) (303); 2.050 (52) (123); 2.016 (29) (321). On the basis of chemical analyses and X-ray data, heklaite corresponds to the synthetic compound KNaSiF6. The name is for the type locality, the Hekla volcano, Iceland.


2021 ◽  
pp. 1-3
Author(s):  
J. Maixner ◽  
J. Ryšavý

X-ray powder diffraction data, unit-cell parameters, and space group for tetrazene nitrate monohydrate, C2H9N11O4, are reported [a = 5.205(1) Å, b = 13.932(3) Å, c = 14.196(4) Å, β = 97.826(3)°, unit-cell volume V = 1019.8(4) Å3, Z = 4, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.


1997 ◽  
Vol 12 (1) ◽  
pp. 47-48 ◽  
Author(s):  
Zong-ming Jin ◽  
Bo Zhao ◽  
Weiqun Zhou ◽  
Zheng Jin

A nonlinear optical material, o–chlorobenzol–benzoyl thiourea (C14H11ClN2OS), has been characterized by X-ray powder diffraction. Experimental values of 2θ corrected for systematic errors, relative peak intensities, values of d, and the Miller indices of 78 observed reflection with 2θ up to 72° are reported. The powder diffraction data have been evaluated, and the figures-of-merit are reported. The unit cell parameters least-squares refined from 28 nonoverlapping peaks of the monoclinic compound with a P2 space group are a=13.2797(4) Å, b=12.4058(8) Å, c=8.1561(2) Å, β=95.398(1)°, V=1337.7(4) Å3, Z=4, Dx=1.444 g/cm3. © 1997 International Centre for Diffraction Data.


2002 ◽  
Vol 17 (1) ◽  
pp. 41-43 ◽  
Author(s):  
Rashmi ◽  
U. Dhawan

ZnGa2Te4 was found to crystallize in a defect tetrahedral structure with possible space group I4(82) with Z=2. Complete X-ray powder diffraction data were obtained and the unit cell parameters a and c and X-ray density were calculated. These were a=0.5930(1) nm, c=1.1859(3) nm, and Dx=5.7×103 kg/m3.


2017 ◽  
Vol 32 (3) ◽  
pp. 203-205
Author(s):  
Xiang Lin ◽  
Wei Ling Zhuo ◽  
Qiao Hong Du ◽  
Xi Lin Peng ◽  
Hui Li

X-ray powder diffraction data, unit-cell parameters, and space group for ertapenem side chain, C20H19N3O7S, are reported [a = 4.907(6) Å, b = 18.686(3) Å, c = 22.071(1) Å, α = γ = 90°, β = 90.759(5)°, unit-cell volume V = 2023.82 Å3, Z = 4, ρcal = 1.462 g cm−3, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurity was observed.


2005 ◽  
Vol 20 (3) ◽  
pp. 203-206 ◽  
Author(s):  
M. Grzywa ◽  
M. Różycka ◽  
W. Łasocha

Potassium tetraperoxomolybdate (VI) K2[Mo(O2)4] was prepared, and its X-ray powder diffraction pattern was recorded at low temperature (258 K). The unit cell parameters were refined to a=10.7891(2) Å, α=64.925(3)°, space group R−3c (167), Z=6. The compound is isostructural with potassium tetraperoxotungstate (VI) K2[W(O2)4] (Stomberg, 1988). The sample of K2[Mo(O2)4] was characterized by analytical investigations, and the results of crystal structure refinement by Rietveld method are presented; final RP and RWP are 9.79% and 12.37%, respectively.


2013 ◽  
Vol 28 (4) ◽  
pp. 296-298
Author(s):  
R. Pažout ◽  
J. Maixner ◽  
A.S. Jones ◽  
J. Merna

X-ray powder diffraction data, unit-cell parameters, and space group for a new bis(β-diiminato) Cu(II) complex, C44H54CuN4O4, are reported [a = 8.683(3) Å, b = 11.216(3) Å, c = 11.753(4) Å, α = 66.27(3), β = 84.61(3), γ = 78.85(3), unit-cell volume V = 1027.77 Å3, Z = 1, and space group P-1]. All measured lines were indexed and are consistent with the P-1 space group. No detectable impurity was observed.


2013 ◽  
Vol 28 (3) ◽  
pp. 231-233 ◽  
Author(s):  
Li Li Zhang ◽  
Qing Qing Pan ◽  
Dan Xiao ◽  
Xiao Qing Wu ◽  
Qing Wang ◽  
...  

X-ray powder diffraction data, unit-cell parameters, and space group for deoxyschisandrin, C24H32O6, are reported [a = 13.083(3) Å, b = 19.563(9) Å, c = 8.805(6) Å, β = 90.472(0)°, unit-cell volume V = 2253.82 Å3, Z = 4, and space group P21]. All measured lines were indexed and are consistent with the P21 space group. No detectable impurity was observed.


2018 ◽  
Vol 64 (6) ◽  
pp. 548
Author(s):  
Gustavo Marroquin ◽  
Gerzon E. Delgado ◽  
Pedro Grima-Gallardo ◽  
Miguel Quintero

The crystal structure of the quaternary compound CuVInSe3 belonging to the system (CuInSe2)1-x(VSe)x with x= ½, was analyzed using X-ray powder diffraction data. This material was synthesized by the melt and anneal method and crystallizes in the tetragonal space group P2c (Nº 112), with unit cell parameters a = 5.7909(4) Å, c = 11.625(1) Å, V = 389.84(5) Å3. The Rietveld refinement of 25 instrumental and structural variables led to Rexp = 6.6 %, Rp = 8.7 %, Rwp = 8.8 % and S = 1.3 for 4501 step intensities and 153 independent reflections. This compound has a normal adamantane structure and is isostructural with CuFeInSe3. The DTA indicates that this compound melts at 1332 K.


2015 ◽  
Vol 30 (2) ◽  
pp. 182-184 ◽  
Author(s):  
R. Pažout ◽  
J. Maixner ◽  
V. Bartůněk

X-ray powder diffraction data, unit cell parameters, and space group for a new organometallic compound, lanthanum trilactate trihydrate, LaC9H21O12, are reported [a = 9.986(1) Å, b = 9.158(1) Å, c = 11.200(1) Å, α = 115.08(1), β = 117.41(1), γ = 88.61(1), unit cell volume V = 804.70 Å3, Z = 2 and space group P1]. All measured lines were indexed. No detectable impurity was observed.


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