Structures of strontium diformate and strontium fumarate. A synchrotron powder diffraction study

2009 ◽  
Vol 65 (4) ◽  
pp. 481-487 ◽  
Author(s):  
Kenny Ståhl ◽  
Jens E. T. Andersen ◽  
Irene Shim ◽  
Stephan Christgau

The crystal structures of strontium diformate in space groups P212121 (α form, 295 K), P41212 (β form, 334 and 540 K) and I41/amd (δ form, 605 K), and strontium fumarate in space groups Fddd (β form, 105 K) and I41/amd (α form, 293 K) have been determined from synchrotron X-ray powder diffraction data. Except for the α-strontium diformate, all the structures are based on a diamond-like Sr-ion arrangement, as in strontium acetylene dicarboxylate. The formate ions are disordered in the δ phase owing to steric hindrance. The fumarate ions are disordered over four (α) or two (β) symmetry-equivalent orientations. α-Strontium fumarate crystallizes with a unique 90° carboxylate dihedral angle, and is stable up to 773 K.

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.


2002 ◽  
Vol 17 (1) ◽  
pp. 1-6 ◽  
Author(s):  
D. Louër ◽  
V. Moise ◽  
M. Liégeois-Duyckaerts ◽  
A. Rulmont

Three phosphates, MIBaIn2(PO4)3 with MI=Na, K, Cs, isostructural to the langbeinite structure, have been studied from powder diffraction data collected with monochromatic radiation obtained from a conventional X-ray source. Precise powder data are reported, as well as cell parameters, i.e., a=10.026 08(9) Å, a=10.121 57(13) Å and a=10.226 94(9) Å for MI=Na, K and Cs, respectively. A Rietveld refinement has been carried out (space group P213), with final RF factors, 0.061, 0.041 and 0.027, and Rwp factors, 0.196, 0.142 and 0.129, for MI=Na, K and Cs, respectively. There are two octahedrally coordinated In3+ ions in the asymmetric unit and the final refinements suggest disorder on the two sites of the MI/Ba sublattice.


1999 ◽  
Vol 14 (4) ◽  
pp. 276-279
Author(s):  
Wiesław Łasocha ◽  
Wiesław Surga ◽  
Alicja Rafalska-Łasocha

The X-ray powder diffraction data of polycrystalline fibrillar zinc trimolybdates ZnMo3O10·3.75H2O, ZnMo3O10·5H2O, and ZnMo3O10·10H2O, are reported. An uncommon diffraction pattern was recorded in the case of the “wet fibers” of ZnMo3O10·10H2O, which could be indexed assuming a model of parallel fibers with translation disorder along the fiber axis. The powder diffraction patterns, lattice parameters, space groups, and other data describing these compounds are presented in this paper.© 1999 International Centre for Diffraction Data.


1987 ◽  
Vol 95 (1102) ◽  
pp. 610-615 ◽  
Author(s):  
Yoshito TAKAKI ◽  
Tomohiko TANIGUCHI ◽  
Hiroshi YAMAGUCHI ◽  
Tomonari OGURA

2017 ◽  
Vol 32 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Alicja Rafalska-Łasocha ◽  
Marta Grzesiak-Nowak ◽  
Piotr Goszczycki ◽  
Katarzyna Ostrowska ◽  
Wiesław Łasocha

Lithol reds belong to the group of azo pigments, which were popular artists’ colouring materials in the first half of the twentieth century. These pigments were also used in many branches of industry. Here, we report X-ray powder diffraction data, unit-cell parameters, and space groups for three compounds from this group: sodium (E)-2-((2-hydroxynaphthalen-1-yl)diazenyl)naphthalene-1-sulphonate monohydrate (Na lithol red), monoclinic, space group C2/c, with cell parameters a = 33.343(7), b = 6.667(2), c = 16.397(4) Å, β = 90.83°, V = 3644.51 Å3, Z = 8; barium (E)-2-[(2-hydroxynaphthalen-1-yl)diazenyl]naphthalene-1-sulphonate trihydrate (Ba lithol red), monoclinic, space group P21/m, with cell parameters a = 17.758(9), b = 6.209(4), c = 16.857(8) Å, β = 92.07°, V = 1857.39 Å3, Z = 2; and ammonium (E)-2-[(2-hydroxynaphthalen-1-yl)diazenyl]naphthalene-1-sulphonate monohydrate (NH4 lithol red), monoclinic, space group P2/c, with cell parameters a = 17.721(5), b = 6.428(3), c = 16.911(5) Å, β = 100.31(3)°, V = 1895.31 Å3, and Z = 4. In the first and third cases we synthesised the pigments in their monohydrate form, performed X-ray powder diffraction measurements, and indexed all of the obtained diffraction maxima. In the case of the barium compound, despite many efforts in the course of the synthesis procedure, the powder diffraction patterns of the obtained samples were not of the best quality. Nevertheless, we indexed the best one and found a reliable space group and cell parameters.


2000 ◽  
Vol 15 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Rashmi ◽  
D. K. Suri

CuInSeTe was synthesized by the melt and anneal technique. The compound crystallized in the chalcopyrite structure having space group I4¯2d with Z=4. Complete X-ray powder diffraction data were obtained and the unit cell parameters a and c, X-ray density and u parameter were calculated. These are a=0.5987(1) nm, c=1.1979(4) nm, Dx=5.96×103kg/m3, and u=0.2498. Atomic positions in the unit cell are proposed.© 2000 International Centre for Diffraction Data.


1995 ◽  
Vol 10 (3) ◽  
pp. 185-188 ◽  
Author(s):  
A. Nørlund Christensen ◽  
P. Norby ◽  
J. C. Hanson

X-ray powder diffraction data for the spinels CoAl2O4 and CoGa2O4 were measured with synchrotron radiation using λ = 1.2033 Å, determined with Si as a standard (a = 5.4305 Å). The two blue compounds prepared hydrothermally are cubic with space group Fd3m. Profile refinements gave the results: CoAl2O4 had a = 8.0968(1) Å and composition (Co0.71Al0.29]Al1.71Co0.29]O4 and CoGa2O4 had a = 8.3229(1) Å and composition Ga[CoGa]O4. The degree of inversion is thus 0.29 for CoAl2O4 and one for CoGa2O4.


2006 ◽  
Vol 21 (4) ◽  
pp. 307-309 ◽  
Author(s):  
František Laufek ◽  
Anna Vymazalová ◽  
František Laufek ◽  
Jakub Plášil

Improved X-ray powder diffraction data for synthetic PdSn are reported. Powder diffraction data were collected with a laboratory X-ray source (CuKα) for Rietveld refinement. Refined crystallographic data for PdSn (orthorhombic, Pnma) are a=6.1388(4), b=3.89226(3), c=6.3377(4) Å, V=151.43(2) Å3, Z=4, and Dx=9.87 g∕cm3.


2015 ◽  
Vol 30 (4) ◽  
pp. 370-371
Author(s):  
J.A. Kaduk ◽  
K. Zhong ◽  
T.N. Blanton ◽  
S. Gates ◽  
T.G. Fawcett

The room-temperature crystal structure of levothyroxine sodium pentahydrate has been refined using synchrotron powder diffraction data. The compound crystallizes in space group P1 (#1) with a = 8.2489(4), b = 9.4868(5), c = 15.8298(6) Å, α = 84.1387(4), β = 83.1560(3), γ = 85.0482(3) deg, V = 1220.071(9) Å3, and Z = 2. Hydrogen atoms (missing from the previously-reported structure) were included.


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