Investigation into the Crystal Structure of the Perovskite Lead Hafnate, PbHfO3

The room-temperature crystal structure of the perovskite lead hafnate PbHfO3 is investigated using both low-temperature single crystal X-ray diffraction (Mo Kα radiation, λ = 0.71069 Å) and polycrystalline neutron diffraction (D1A instrument, ILL, λ = 1.90788 Å). Single crystal X-ray data at 100 K: space group Pbam, a = 5.856 (1), b = 11.729 (3), c = 8.212 (2) Å, V = 564.04 Å3 with Z = 8, μ = 97.2 mm−1, F(000) = 1424, final R = 0.038, wR = 0.045 over 439 reflections with F >1.4σ(F). Polycrystalline neutron data at 383 K: a = 5.8582 (3), b = 11.7224 (5), c = 8.2246 (3) Å, V = 564.80 Å3 with χ2 = 1.62. Although lead hafnate has been thought to be isostructural with lead zirconate, no complete structure determination has been reported, as crystal structure analysis in both these materials is not straightforward. One of the main difficulties encountered is the determination of the oxygen positions, as necessary information lies in extremely weak l = 2n + 1 X-ray reflections. To maximize the intensity of these reflections the X-ray data are collected at 100 K with unusually long scans, a procedure which had previously been found successful with lead zirconate. In order to establish that no phase transitions exist between room temperature and 100 K, and hence that the collected X-ray data are relevant to the room-temperature structure, birefringence measurements for both PbZrO3 and PbHfO3 are also reported.

Download Full-text

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

10.26434/chemrxiv.11345063.v2 ◽

2020 ◽

Author(s):

Keishiro Yamashita ◽

Kazuki Komatsu ◽

Hiroyuki Kagi

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Crystal Growth ◽

Single Crystal ◽

Room Temperature ◽

Growth Technique ◽

Salt Hydrate ◽

X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

Download Full-text

Crystal Structure Analysis of the First Discovered Stability-Enhanced Solid State of Tenofovir Disoproxil Free Base Using Single Crystal X-ray Diffraction

Molecules ◽

10.3390/molecules22071182 ◽

2017 ◽

Vol 22 (7) ◽

pp. 1182 ◽

Cited By ~ 2

Author(s):

Ji-Hun An ◽

Alice Kiyonga ◽

Woojin Yoon ◽

Hyung Ryu ◽

Jae-Sun Kim ◽

...

Keyword(s):

Crystal Structure ◽

Solid State ◽

Single Crystal ◽

Structure Analysis ◽

Crystal Structure Analysis ◽

Free Base ◽

X Ray Diffraction ◽

X Ray

Download Full-text

Evolution of crystal structure of dual layered molecular conductor (ET)4ZnBr4(C6H4Cl2) with temperature

CrystEngComm ◽

10.1039/d1ce00902h ◽

2021 ◽

Author(s):

Gennady V. Shilov ◽

Elena I. Zhilyaeva ◽

Sergey M. Aldoshin ◽

Alexandra M Flakina ◽

Rustem B. Lyubovskii ◽

...

Keyword(s):

Crystal Structure ◽

Electrical Resistivity ◽

Single Crystal ◽

Room Temperature ◽

Organic Conductor ◽

X Ray Diffraction ◽

X Ray ◽

Resistivity Measurements ◽

Molecular Conductor ◽

Abrupt Changes

Electrical resistivity measurements of a dual layered organic conductor (ET)4ZnBr4(1,2-C6H4Cl2) above room temperature show abrupt changes in resistivity at 320 K. Single-crystal X-ray diffraction studies in the 100-350 K range...

Download Full-text

Magnetically Oriented Powder Crystal to Indexing and Structure Determination

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314084393 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C1560-C1560

Author(s):

Fumiko Kimura ◽

Wataru Oshima ◽

Hiroko Matsumoto ◽

Hidehiro Uekusa ◽

Kazuaki Aburaya ◽

...

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Crystal Lattice ◽

Powder Diffraction ◽

Diffraction Method ◽

Lattice Parameters ◽

X Ray Diffraction ◽

X Ray ◽

Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

Download Full-text

Rubidium tetrafluoridobromate(III): redetermination of the crystal structure from single-crystal X-ray diffraction data

IUCrData ◽

10.1107/s2414314619015955 ◽

2019 ◽

Vol 4 (11) ◽

Author(s):

Artem V. Malin ◽

Sergei I. Ivlev ◽

Roman V. Ostvald ◽

Florian Kraus

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Single Crystals ◽

Diffraction Data ◽

Structure Type ◽

X Ray Diffraction ◽

X Ray ◽

Square Planar ◽

Atomic Coordinates

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].

Download Full-text

X-ray Diffraction Residual Stress Measurement at Room Temperature and 77 K in a Microelectronic Multi-layered Single-Crystal Structure Used for Infrared Detection

Journal of Electronic Materials ◽

10.1007/s11664-018-6560-7 ◽

2018 ◽

Vol 47 (11) ◽

pp. 6641-6648 ◽

Cited By ~ 1

Author(s):

A.-L. Lebaudy ◽

R. Pesci ◽

M. Fendler

Keyword(s):

Crystal Structure ◽

Residual Stress ◽

Single Crystal ◽

Room Temperature ◽

Stress Measurement ◽

Single Crystal Structure ◽

Residual Stress Measurement ◽

Infrared Detection ◽

X Ray Diffraction ◽

X Ray

Download Full-text

The caesium phosphates Cs3(H1.5PO4)2(H2O)2, Cs3(H1.5PO4)2, Cs4P2O7(H2O)4, and CsPO3

Monatshefte für Chemie - Chemical Monthly ◽

10.1007/s00706-020-02675-6 ◽

2020 ◽

Vol 151 (9) ◽

pp. 1317-1328

Author(s):

Matthias Weil ◽

Berthold Stöger

Keyword(s):

Crystal Structure ◽

Hydrogen Bond ◽

Single Crystal ◽

Diffraction Data ◽

Room Temperature ◽

Structure Type ◽

Solid State Reactions ◽

X Ray Diffraction ◽

Hydrogen Phosphate ◽

X Ray

Abstract The caesium phosphates Cs3(H1.5PO4)2(H2O)2 and Cs3(H1.5PO4)2 were obtained from aqueous solutions, and Cs4P2O7(H2O)4 and CsPO3 from solid state reactions, respectively. Cs3(H1.5PO4)2, Cs4P2O7(H2O)4, and CsPO3 were fully structurally characterized for the first time on basis of single-crystal X-ray diffraction data recorded at − 173 °C. Monoclinic Cs3(H1.5PO4)2 (Z = 2, C2/m) represents a new structure type and comprises hydrogen phosphate groups involved in the formation of a strong non-symmetrical hydrogen bond (accompanied by a disordered H atom over a twofold rotation axis) and a very strong symmetric hydrogen bond (with the H atom situated on an inversion centre) with symmetry-related neighbouring anions. Triclinic Cs4P2O7(H2O)4 (Z = 2, P$$\bar{1}$$ 1 ¯ ) crystallizes also in a new structure type and is represented by a diphosphate group with a P–O–P bridging angle of 128.5°. Although H atoms of the water molecules were not modelled, O···O distances point to hydrogen bonds of medium strengths in the crystal structure. CsPO3 is monoclinic (Z = 4, P21/n) and belongs to the family of catena-polyphosphates (MPO3)n with a repetition period of 2. It is isotypic with the room-temperature modification of RbPO3. The crystal structure of Cs3(H1.5PO4)2(H2O)2 was re-evaluated on the basis of single-crystal X-ray diffraction data at − 173 °C, revealing that two adjacent hydrogen phosphate anions are connected by a very strong and non-symmetrical hydrogen bond, in contrast to the previously described symmetrical bonding situation derived from room temperature X-ray diffraction data. In the four title crystal structures, coordination numbers of the caesium cations range from 7 to 12. Graphic abstract

Download Full-text

A fourfold interpenetrating diamond-like three-dimensional zinc(II) coordination polymer: synthesis, crystal structure and physical properties

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229619004303 ◽

2019 ◽

Vol 75 (5) ◽

pp. 504-507 ◽

Cited By ~ 2

Author(s):

Hui-Ru Chen

Keyword(s):

Crystal Structure ◽

Room Temperature ◽

Three Dimensional ◽

Fluorescence Emission ◽

Crystal Structure Analysis ◽

The Novel ◽

X Ray Diffraction ◽

Metal Compounds ◽

X Ray ◽

Coordination Framework

Excellent fluorescence properties are exhibited by d 10 metal compounds. The novel three-dimensional ZnII coordination framework, poly[[{μ2-bis[4-(2-methyl-1H-imidazol-1-yl)phenyl] ether-κ2 N 3:N 3′}(μ2-furan-2,5-dicarboxylato-κ2 O 2:O 5)zinc(II)] 1.76-hydrate], {[Zn(C6H2O5)(C20H18N4O)]·1.76H2O} n , has been prepared and characterized using IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The crystal structure analysis revealed that the compound exhibits a novel fourfold interpenetrating diamond-like network. This polymer also displays a strong fluorescence emission in the solid state at room temperature.

Download Full-text