Über ein Barium-Lanthanoid-Oxozinkat-Platinat(IV): Ba17Yb16Zn8Pt4O57

1996 ◽  
Vol 51 (2) ◽  
pp. 220-224 ◽  
Author(s):  
Ch. Rabbow ◽  
O. Sfreddo ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Space Group ◽  
Structure Space ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Trigonal Prismatic Coordination ◽  
The Relationship ◽  
Trigonal Prismatic

Abstract Reactions of BaCO3, ZnO and Yb2O3 mixtures at temperatures up to 1300 °C using plati­num crucibles led to yellow needles of Ba17Y b16Zn8Pt4O57. The compound crystallizes with a hitherto unknown tetragonal crystal structure, space group C54h-I4/m, a = 22.731(1), c = 5.682(1) Å , Z = 2. The crystal structure is characterized by PtO6 octahedra and tetragonal ZnO5 pyramids. Yb3+ shows a mono-capped trigonal prismatic coordination and Ba2+ several different coordination environments (C .N = 9 to 10, by O2-). The relationship to the Ba5Ln8M4O21 type is discussed.

scholarly journals High temperature tetragonal crystal structure of UPt2Si2

2020 ◽  
Vol 235 (6-7) ◽  
pp. 175-181
Author(s):  
Karel Prokeš ◽  
Oscar Fabelo ◽  
Stefan Süllow ◽  
Jooseop Lee ◽  
John A. Mydosh
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Space Group ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure

AbstractHigh temperature crystal structure of UPt2Si2 determined using single-crystal neutron diffraction at 400 K is reported. It is found that the crystal structure remains of the primitive tetragonal CaBe2Ge2 type with the space group P4/nmm. Anisotropic displacement factors of the Pt atoms at the 2a (3/4 1/4 0) and Si atoms at the 2c (1/4 1/4 z) Wyckoff sites are found to be anomalously large.

scholarly journals Crystal Structures of New Ivermectin Pseudopolymorphs

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Kirill Shubin ◽  
Agris Bērziņš ◽  
Sergey Belyakov
Keyword(s):  
Crystal Structure ◽  
Molecular Conformation ◽  
Methyl Tert Butyl Ether ◽  
Minor Role ◽  
Scanning Calorimetry ◽  
Orthorhombic Crystal ◽  
Monoclinic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Space Group ◽  
Structure Space

New pseudopolymorphs of ivermectin (IVM), a potential anti-COVID-19 drug, were prepared. The crystal structure for three pseudopolymorphic crystalline forms of IVM has been determined using single-crystal X-ray crystallographic analysis. The molecular conformation of IVM in crystals has been compared with the conformation of isolated molecules modeled by DFT calculations. In a solvent with relatively small molecules (ethanol), IVM forms monoclinic crystal structure (space group I2), which contains two types of voids. When crystallized from solvents with larger molecules, like γ-valerolactone (GVL) and methyl tert-butyl ether (MTBE), IVM forms orthorhombic crystal structure (space group P212121). Calculations of the lattice energy indicate that interactions between IVM and solvents play a minor role; the main contribution to energy is made by the interactions between the molecules of IVM itself, which form a framework in the crystal structure. Interactions between IVM and molecules of solvents were evaluated using Hirshfeld surface analysis. Thermal analysis of the new pseudopolymorphs of IVM was performed by differential scanning calorimetry and thermogravimetric analysis.

scholarly journals (R)-Baclofen [(R)-4-amino-3-(4-chlorophenyl)butanoic acid]

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Feodor Belov ◽  
Alexander Villinger ◽  
Jan von Langermann
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Title Compound ◽  
Single Crystal Xrd ◽  
Butanoic Acid ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Space Group ◽  
Structure Space

This article provides the first single-crystal XRD-based structure of enantiopure (R)-baclofen (form C), C10H12ClNO2, without any co-crystallized substances. In the enantiopure title compound, the molecules arrange themselves in an orthorhombic crystal structure (space group P212121). In the crystal, strong hydrogen bonds and C—H ... Cl bonds interconnect the zwitterionic molecules.

Novel three-dimensional coordination polymers of lanthanides with sulfate and oxydiacetic acid

2013 ◽  
Vol 69 (12) ◽  
pp. 1503-1508 ◽  
Author(s):  
Thazhe Kootteri Prasad ◽  
M. V. Rajasekharan
Keyword(s):  
Crystal Structure ◽  
Coordination Polymers ◽  
Three Dimensional ◽  
Lanthanide Oxides ◽  
Coordination Polyhedra ◽  
Hydrothermal Reactions ◽  
Lanthanide Cations ◽  
Trigonal Prismatic Coordination ◽  
Oxydiacetic Acid ◽  
Trigonal Prismatic

Three three-dimensional coordination polymers,viz.poly[[diaqua-μ4-oxydiacetato-di-μ4-sulfato-dipraseodymium(III)] hemihydrate], [Pr2(C4H4O5)(SO4)2(H2O)2]·0.5H2O, (I), poly[[diaquadi-μ3-oxydiacetato-μ3-sulfato-dineodymium(III)] 1.32-hydrate], [Nd2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (II), and poly[[diaquadi-μ3-oxydiacetato-μ3-sulfato-disamarium(III)] 1.32-hydrate], [Sm2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (III), were obtained by hydrothermal reactions of the respective lanthanide oxides and ZnSO4with oxydiacetic acid (odaH2). The Nd3+and Sm3+compounds form isomorphous crystal structures in which the lanthanide cations are nine-coordinate, having a tricapped trigonal prismatic coordination. The Pr3+compound has an entirely different crystal structure in which two types of coordination polyhedra are observed,viz.nine-coordinate (trigonal prism) and ten-coordinate (bicapped square antiprism). The sulfate anions show various coordination modes, one of which has only rarely been observed crystallographically to date.

Ein tricyclisches Tetraboradisiladodecan aus Dimethyl-di-1-propinylsilan und Ethyldiboranen(6) / A Tricyclic Tetraboradisiladodecane from Dimethyl-di-1-propynylsilane and Ethyldiboranes(6)

1995 ◽  
Vol 50 (3) ◽  
pp. 439-447 ◽  
Author(s):  
Roland Köster ◽  
Günter Seidel ◽  
Roland Boese ◽  
Bernd Wrackmeyer
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
Thermal Elimination

The exhaustive hydroboration of the (C ≡ C )-groups in Me2Si(C ≡ CMe)2 (A ) by adding ethyldiboranes(6) at room temperature is presumed to lead initially to the formation of a mixture of the threo- and erythro-3,3,5,6-tetrakis(diethylboryl)-4,4-dimethyl-4-silaheptanes (1a , b). The threo-1a reacts further by borane catalysed intermolecular condensation to the substituted disilatetraboratricyclo[6.2.1.16.9]dodecane 2 with the formula , whose crystal structure [space group C2/c, a = 19.696(2), b = 10.371(1), c = 16.580(2) Å; β = 125.90(1)°; at 122 K] has been established by X -ray diffraction. In contrast, the erythro-1b undergoes intramolecular, thermal elimination of Et3B to give the 1,2-diethyl-2,4-bis(diethylboryl)- 3,3,5-trim ethyl-3-silaborolane (4). If A is added to an excess of undiluted B (“hydridebath”), then the two substituted diastereomers of the 1-carba-arachno-pentaboranes(10) (endo/exo-Et,SiH Me2) (3a, b), are formed preferentially as the result of an initial Si-C ≡-c le a v e d hydroboration.

Darstellung und Struktur der Verbindungen MgCuP, BaCuP(As) und BaAgP(As) / Preparation and Crystal Structure of MgCuP, BaCuP(As), and BaAgP(As)

1979 ◽  
Vol 34 (10) ◽  
pp. 1373-1376 ◽  
Author(s):  
Albrecht Mewis
Keyword(s):  
Crystal Structure ◽  
Space Group ◽  
Lattice Constants ◽  
Structure Space

Abstract The ABX-compounds MgCuP, BaCuP(As) and BaAgP(As) have been prepared and their structures determined. MgCuP crystallizes orthorhombically in an anti-PbCl2-structure (space group Pnma-D162h, a = 653.2(1) pm, b - 383.5(1) pm, c = 717.0(1) pm). The compounds BaCuP(As) and BaAgP(As) are isotypic and crystallize in a modified Ni2ln-structure (space group P63/mmc-D46h) with the lattice constants:BaCuP a = 423.9(1) pm, c = 900.6(2) pm,BaCuAs a = 437.2(1) pm, c = 907.3(2) pm,BaAgP a = 449.6(1) pm, c = 882.8(2) pm,BaAgAs a = 461.3(1 )pm, c = 889.6(1) pm.

scholarly journals New Compounds RE(Zn,Al)8 and Yb4Zn20.3Al12.7 and their Crystal Structures

2006 ◽  
Vol 61 (7) ◽  
pp. 779-784 ◽  
Author(s):  
Ol’ga Stel’makhovych ◽  
Yurij Kuz’ma
Keyword(s):  
Intermetallic Compound ◽  
Crystal Structures ◽  
Structure Type ◽  
Type Structure ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
New Compounds ◽  
First Time ◽  
The Relationship

The crystal structures of several new compounds have been determined using X-ray analysis. The intermetallic compound HoZn5Al3 (a = 8.586(3), c = 16.538(5) Å , RF = 0.0413, RW = 0.0521) has its own structure type (space group I4/mmm), which has been found for the first time. The following compounds are isostructural with the previous one: YZn5.52Al2.48 (a = 8.6183(1), c = 16.5048(3) Å , RI = 0.078, RP = 0.116), DyZn4.96Al3.04 (a = 8.5887(1), c = 16.5002(3) Å , RI = 0.077, RP = 0.114), ErZn5.37Al2.63 (a = 8.5525(2), c =16.3997(5) Å , RI = 0.081, RP = 0.111), TmZn5.64Al2.36 (a = 8.70429(8), c = 16.3943(4) Å , RI = 0.088, RP = 0.095), LuZn5.58Al2.42 (a = 8.5616(1), c= 16.3052(3) Å , RI =0.081, RP =0.101). The intermetallic compound Yb4Zn20.3Al12.7 (a = 8.6183(1), c = 16.5048(3) Å , RI = 0.085, RP = 0.112) adopts the Yb8Cu17Al49 - type structure (space group I4/mmm). The relationship between the HoZn5Al3-type and the Yb8Cu17Al49-type structures is discussed.

Neutron Powder Diffraction on Ce11B2C2and Nd11B2C2: A New Model for the Tetragonal Crystal Structure

1999 ◽  
Vol 68 (7) ◽  
pp. 2287-2291 ◽  
Author(s):  
Takahiro Onimaru ◽  
Hideya Onodera ◽  
Kenji Ohoyama ◽  
Hiroki Yamauchi ◽  
Yasuo Yamaguchi
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
New Model ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure

Studied on Structural Characterization of Lanthanum Doped Barium Titanium Ceramics

2015 ◽  
Vol 819 ◽  
pp. 198-203
Author(s):  
Nur Farahin Abdul Hamid ◽  
Rozana Aina Maulat Osman ◽  
Mohd Sobri Idris ◽  
Tze Qing Tan
Keyword(s):  
Crystal Structure ◽  
Lattice Parameter ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
La Doped ◽  
Conventional Solid State Synthesis

La-doped barium titanate (BaTiO3) was prepared using conventional solid state synthesis route. All peaks for sample x=0 are approaching the phase pure of BaTiO3 structure with tetragonal crystal structure (P4mm). Sintering of pressed powder are performed at 1300oC, 1400oC and 1450oC for overnight for pure BaTiO3 and 1350oC for 3 days for BaTiO3 doped lanthanum with intermittent grinding. Phase transition was studied by different x composition. The changes in the crystal structure of the composition x=0.1 and 0.2 were detected by using X-ray diffraction (XRD). The phase changes between tetragonal-cubic and cubic-tetragonal depending on the temperature. Rietveld Refinement analysis is carried out to determine the lattice parameter and unit cell for BaTiO3.

scholarly journals Darstellung und Kristallstruktur von Palladiumoxidchlorid Pd2OCl2/Preparation and Crystal Structure of Palladium Oxide Chloride Pd2OCl2

1986 ◽  
Vol 41 (11) ◽  
pp. 1363-1366 ◽  
Author(s):  
Beate Dannecker ◽  
Gerhard Thiele
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Palladium Oxide ◽  
Compound A ◽  
Space Group ◽  
Square Planar ◽  
The Relationship

Abstract Pd2OCl2 was obtained by reaction of γ-PdCl2 and PdO·nH2O in a KNO3/NaNO3 melt at 450 °C. Single crystals were grown from a TlCl flux. The crystal structure of the tetragonal compound (a = 631.3(2) pm, c = 987.2(2) pm, space group I41 /amd) is built up from bands of edge shared square planar PdO2Cl2 groups connected by common O-atoms to a framework. The relationship between the structures of Pd2OCl2 and PdO is discussed.

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