Darstellung und Kristallstruktur von K49Tl108 / Preparation and Crystal Structure of K49T1108

1993 ◽  
Vol 48 (8) ◽  
pp. 1035-1040 ◽  
Author(s):  
Gerhard Cordier ◽  
Volker Müller

K49T1108 was prepared from the elements (molar ratio K: Tl = 1:2) at 700 K. The crystal structure was determined by single crystal X-ray diffraction methods (a = 1728.7(1) pm, Pm 3, Z = 1, R = 0.086). It contains T112 icosahedra and Tl12 truncated tetrahedra (Kasper polyhedra). 20 truncated tetrahedra form Tl84-polyhedra (Samson polyhedra) by sharing hexagonal faces. These polyhedra are connected by common edges. Folded Tl13-chains connect the icosahedra and the Samson polyhedra to a framework. The truncated tetrahedra are occupied by potassium atoms.

2011 ◽  
Vol 66 (11) ◽  
pp. 1087-1091 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo

Colorless and transparent single crystals of Ba2H3I were obtained by reacting Ba with dried and sublimed NH4I in a 4 : 1 molar ratio in silica-jacketed Nb ampoules at 1100 K for 13 h. The crystal structure of the title compound was determined and refined by means of single-crystal X-ray diffraction. Ba2H3I crystallizes in a stuffed anti-CdI2 structure isotypic to Sr2H3I in the space group P3̄m1 (no. 164) with the lattice parameters a = 451.86(12) and c = 811.84(23) pm. The structural results for Ba2H3I are consistent with bond lengths and coordination geometries of related binary and ternary hydrides


2017 ◽  
Vol 72 (7) ◽  
pp. 505-510
Author(s):  
Hamdi Ben Yahia ◽  
Masahiro Shikano ◽  
Ilias Belharouak

AbstractThe new compound Co9(OH)14[SO4]2 was synthesized using a hydrothermal method from LiF, Na2SO3, and Co(CH3COO)2·4H2O in a molar ratio of 1:1:1 in the presence of atmospheric oxygen. Its crystal structure was determined from single crystal X-ray diffraction data. Co9(OH)14[SO4]2 crystallizes in the triclinic system, space group P1̅ with a=7.693(2) Å, b=8.318(2) Å, c=8.351(2) Å, α=82.375(5)°, β=77.832(4)°, γ=68.395(4)°, V=484.8(2) Å3, and Z=2. Its structure is composed of cobalt-containing sheets interconnected by SO4 tetrahedra. Bent and symmetrically trifurcated hydrogen bonds have been observed. Furthermore, structural similarities with hydrozincite and brucite minerals have been noticed.


2002 ◽  
Vol 57 (8) ◽  
pp. 890-894 ◽  
Author(s):  
Hendrik Ehlich ◽  
Annette Schier ◽  
Hubert Schmidbaur

The reaction of (isocyanide)gold(I) chlorides [(RNC)AuCl, R = tBu, cHex] with phenylene- 1,2-dithiol and sodium methoxide (molar ratio 2:1:2) in methanol / dichloromethane leads to the formation of deep green mixed-valent salts [(RNC)2Au]+[Au(S2C6H4)2]- in ca. 35% yield. As determined by single crystal X-ray diffraction methods, the two compounds have entirely different supramolecular structures. For R = tBu stacked planar anions and rod-like cations form alternating layers, while for R = cHex alternating cations and anions are arranged in chains with long S- -Au contacts [3.422 Å].


Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group


2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.


Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 272
Author(s):  
Seungyeol Lee ◽  
Huifang Xu ◽  
Hongwu Xu ◽  
Joerg Neuefeind

The crystal structure of moganite from the Mogán formation on Gran Canaria has been re-investigated using high-resolution synchrotron X-ray diffraction (XRD) and X-ray/neutron pair distribution function (PDF) analyses. Our study for the first time reports the anisotropic atomic displacement parameters (ADPs) of a natural moganite. Rietveld analysis of synchrotron XRD data determined the crystal structure of moganite with the space group I2/a. The refined unit-cell parameters are a = 8.7363(8), b = 4.8688(5), c = 10.7203(9) Å, and β = 90.212(4)°. The ADPs of Si and O in moganite were obtained from X-ray and neutron PDF analyses. The shapes and orientations of the anisotropic ellipsoids determined from X-ray and neutron measurements are similar. The anisotropic ellipsoids for O extend along planes perpendicular to the Si-Si axis of corner-sharing SiO4 tetrahedra, suggesting precession-like movement. Neutron PDF result confirms the occurrence of OH over some of the tetrahedral sites. We postulate that moganite nanomineral is stable with respect to quartz in hypersaline water. The ADPs of moganite show a similar trend as those of quartz determined by single-crystal XRD. In short, the combined methods can provide high-quality structural parameters of moganite nanomineral, including its ADPs and extra OH position at the surface. This approach can be used as an alternative means for solving the structures of crystals that are not large enough for single-crystal XRD measurements, such as fine-grained and nanocrystalline minerals formed in various geological environments.


2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.


2010 ◽  
Vol 95 (4) ◽  
pp. 655-658 ◽  
Author(s):  
S. Nazzareni ◽  
P. Comodi ◽  
L. Bindi ◽  
L. Dubrovinsky

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