Crystal structure determination of K2Zn(PO3)4

2009 ◽  
Vol 24 (1) ◽  
pp. 4-7 ◽  
Author(s):  
L. N. Ji ◽  
Y. Q. Chen ◽  
J. B. Li ◽  
J. Luo ◽  
J. K. Liang ◽  
...  

The crystal structure of K2Zn(PO3)4 was determined and refined using the Rietveld method based on the isostructure model of K2Cu(PO3)4. This compound belongs to the monoclinic system with space group Cc and lattice parameters of a=11.0941(2) Å, b=12.5215(3) Å, c=7.6597(2) Å, and β=102.47(2)°. The chemical formula unit per unit cell is Z=4 and the calculated density is 2.938(3) g∕cm3. Zigzag [PO3]∞ chains formed along the a axis, and their period contains eight PO4 tetrahedrons.

2020 ◽  
Vol 84 (5) ◽  
pp. 699-704
Author(s):  
Luca Bindi ◽  
Andrew C. Roberts ◽  
Cristian Biagioni

AbstractAlstonite, BaCa(CO3)2, is a mineral described almost two centuries ago. It is widespread in Nature and forms magnificent cm-sized crystals. Notwithstanding, its crystal structure was still unknown. Here, we report the crystal-structure determination of the mineral and discuss it in relationship to other polymorphs of BaCa(CO3)2. Alstonite is trigonal, space group P31m, with unit-cell parameters a = 17.4360(6), c = 6.1295(2) Å, V = 1613.80(9) Å3 and Z = 12. The crystal structure was solved and refined to R1 = 0.0727 on the basis of 4515 reflections with Fo > 4σ(Fo) and 195 refined parameters. Alstonite is formed by the alternation, along c, of Ba-dominant and Ca-dominant layers, separated by CO3 groups parallel to {0001}. The main take-home message is to show that not all structure determinations of minerals/compounds can be solved routinely. Some crystals, even large ones displaying excellent diffraction quality, can be twinned in complex ways, thus making their study a crystallographic challenge.


2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.


1983 ◽  
Vol 38 (5) ◽  
pp. 554-558 ◽  
Author(s):  
Herbert Binder ◽  
Walter Matheis ◽  
Hans-Jörg Deiseroth ◽  
Han Fu-Son

Abstract Acyloxyfluoroboranes Trimeric alkoxydifluoroboranes (F2BOR)3 (2) react with organic acid anhydrides by substitution of a ring group OR forming monocyclic acyloxyfluoroboranes of the type 2,2,6,6-tetrafluoro-l,4-dialkyl-l,3,5-trioxa-2,6-diboracyclohexene (3). The X-ray crystal structure determination of 3a shows two conformational isomers: two planar and two non-planar six-membered rings are present in the unit cell. The ring conformation is influenced by weak intermolecular H — F interactions.


1993 ◽  
Vol 48 (7) ◽  
pp. 1009-1012 ◽  
Author(s):  
Kurt Merzweiler ◽  
Harald Kraus

[{Cp(CO)2Fe}SnCl3] reacts with Na2Se in THF to form the compound [{Cp(CO)2Fe}3ClSn3Se4] 1. 1 crystallizes in the monoclinic space group P21/n with 4 formula units per unit cell. The lattice constants are α = 1435.2(7), b = 1124.4(4), c = 1972.7(12) pm, β = 94.59(4)°. According to the X-ray structure determination 1 contains a bicyclic Sn3Se4 framework.


1995 ◽  
Vol 2 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Angel Garcia-Raso ◽  
Juan J. Fiol ◽  
Elies Molins ◽  
Antonia M. Calafat ◽  
Patricia A. Marzilli ◽  
...  

The first X-ray structure of an isatin (2,3-indolinedione, isaH) metal complex, bis(isatinato)memury(II) (C16H8N2O4Hg) (1), was determined. (1) was obtained from the reaction of isaH with mercury(II) acetate in methanol. Analogously, treatment of sodium saccharinate and mercury(II) acetate in methanol yielded Hg(saccharinato)2•0.5CH3OH (3). (1) crystallizes in the monoclinic system, space group P21/a with a = 7.299(1) Å, b = 8.192(1) Å, c = 11.601(1) Å , β = 105.82(1)°, V = 667.4 Å3, Z = 2, Dcalc = 2.452 g cm−3, MoKα radiation(λ = 0.71073 Å), μ = 115.5 cm-1, F(000) = 460, 21(1) °C. The structure was refined on the basis of 2023 observed reflections to R= 0.044. The two deprotonated, non coplanar isa ligands are trans to each other in a head to tail orientation and bound to the Hg through the nitrogen in a linear N-Hg-N arrangement. The Hg atom is at the center of symmetry of the complex and displaced by 0.62 Å from the two planes of the isa ligands (τ Hg-N1-C2-O2= -16°). The Hg-N bond length is 2.015 Å. Noπ-aryl-memury(ll)-π-aryl stacking interaction was observed either in the solid state or in the solution state. The IR, electronic, and H1 and C13NMR spectral data of (1) and (3) suggest binding of the memury to the heterocyclic nitrogen, in agreement with the crystal structure determination of (1).


1998 ◽  
Vol 53 (8) ◽  
pp. 816-818 ◽  
Author(s):  
W. Preetz ◽  
S. Zander ◽  
C. Bruhn

Abstract By reaction of [B6H6]2-with (SCN)2 in dichloromethane at -80 C° the thiocyanatohexaborate anion is formed and can be isolated by ion exchange chromatography on diethylaminoethyl (DEAE) cellulose. The X-ray structure determination of Cs2[B6H5(SCN)] (orthorhombic, space group Pbca with a = 9.506(5), b = 10.644(5), c = 21.857(5) Å, Z = 8) reveals that the SCN substituent is bonded via the S atom with the B-S distance of 1.885(9) Å and the B-S-C angle of 99.8(5)°. The SCN group is nearly linear (179.9(9)°).


1988 ◽  
Vol 43 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Dieter Fenske ◽  
Eberhard Böhm ◽  
Kurt Dehnicke ◽  
Joachim Strähle

Abstract The title compound has been prepared by the reaction of N-trimethylsilyl-iminotriphenylphos-phorane with copper(II) chloride in boiling CCl4 /C2H5OH, and forms moisture sensitive crystals, which are green in transmittance and black in reflexion. [Me3SiNPPh3 · CuCl2 ] 2 was characterized by its IR spectrum as well as by a crystal structure determination (4197 observed, independent reflexions, R = 0.049). The lattice dimensions are at 20 °C: a = 1102.7. b = 1407.3. c = 1560.2 pm; β = 94.27°; space group P21/n with two formula units in the unit cell. The complex consists of centrosymmetric, dimeric molecules with a planar Cu2 Cl2 ring (Cu-CI bond lengths 229 and 231 pm). A terminally bonded CI atom (Cu-CI = 221 pm) and the N atom of the Me3SiNPPh3 ligand (Cu-N = 198.5 pm) complete the coordination number four of the nearly planar surroundings of the Cu atoms.


2015 ◽  
Vol 30 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Chao Zeng ◽  
Guoqiang Lin ◽  
Weijing Zeng ◽  
Wei He

The crystal structure of new Tb3CuAl3Ge2 quaternary compound was studied by the Rietveld method from powder X-ray diffraction (XRD) data. The Tb3CuAl3Ge2 compound crystallized in the hexagonal Y3NiAl3Ge2-type structure with space group P-62m (no. 189) and lattice parameters a = 7.0041(2) Å, c = 4.1775(1) Å, V = 177.48 Å3. There is only one formula in each unit cell, Z = 1, and the density of Tb3CuAl3Ge2 is ρx = 7.1696 g cm−3. The reliability factors characterizing the Rietveld refinement results are Rp = 6.43%, Rwp = 8.65%, RB = 4.81%, and RF = 4.09%, respectively. The powder XRD data of Tb3CuAl3Ge2 were presented and the reliability of indexation is F30 = 120.9(0.0073, 34).


2019 ◽  
Vol 65 (4 Jul-Aug) ◽  
pp. 360 ◽  
Author(s):  
G. E. Delgado ◽  
C. Rincón ◽  
G. Marroquin

The crystal structure of the ordered vacancy compound (OVC) Cu3In5Te9 was analyzed using powder X-ray diffraction data. Several structural models were derived from the structure of the Cu-poor Cu-In-Se compound b-Cu0.39In1.2Se2 by permuting the cations in the available site positions. The refinement of the best model by the Rietveld method in the tetragonal space group P2c (Nº 112), with unit cell parameters a = 6.1852(2) Å, c = 12.3633(9) Å, V = 472.98(4) Å3, led to Rp = 7.1 %, Rwp = 8.5 %, Rexp = 6.4 %, S = 1.3 for 162 independent reflections. This model has the following Wyckoff site atomic distribution: Cu1 in 2e (0,0,0); In1 in 2f (½,½,0), In2 in 2d (0,½,¼); Cu2-In3 in 2b (½,0,¼); in 2a (0,0,¼); Te in 8n (x,y,z).


Author(s):  
Dengke Tian ◽  
Xueqi Fu ◽  
Wenqiang Cao ◽  
Hong Yuan

Gluconate 5-dehydrogenase (Ga5DH; EC 1.1.1.69) from Lentibacter algarum (LaGa5DH) was recombinantly expressed in Escherichia coli and purified to homogeneity. The protein was crystallized and the crystal structure was solved at 2.1 Å resolution. The crystal belonged to the monoclinic system, with space group P1 and unit-cell parameters a = 55.42, b = 55.48, c = 79.16 Å, α = 100.51, β = 105.66, γ = 97.99°. The structure revealed LaGaDH to be a tetramer, with each subunit consisting of six α-helices and three antiparallel β-hairpins. LaGa5DH has high structural similarity to other Ga5DH proteins, demonstrating that this enzyme is highly conserved.


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