scholarly journals NewM+,M3+-arsenates – the framework structures of AgM3+(HAsO4)2(M3+= Al, Ga) andM+GaAs2O7(M+= Na, Ag)

2017 ◽  
Vol 73 (5) ◽  
pp. 785-790 ◽  
Author(s):  
Karolina Schwendtner ◽  
Uwe Kolitsch
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Diffraction Data ◽  
Room Temperature ◽  
Three Dimensional ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Donor Acceptor ◽  
Anionic Framework

The crystal structures of hydrothermally synthesized silver(I) aluminium bis[hydrogen arsenate(V)], AgAl(HAsO4)2, silver(I) gallium bis[hydrogen arsenate(V)], AgGa(HAsO4)2, silver gallium diarsenate(V), AgGaAs2O7, and sodium gallium diarsenate(V), NaGaAs2O7, were determined from single-crystal X-ray diffraction data collected at room temperature. The first two compounds are representatives of the MCV-3 structure type known for KSc(HAsO4)2, which is characterized by a three-dimensional anionic framework of corner-sharing alternatingM3+O6octahedra (M= Al, Ga) and singly protonated AsO4tetrahedra. Intersecting channels parallel to [101] and [110] host the Ag+cations, which are positionally disordered in the Ga compound, but not in the Al compound. The hydrogen bonds are relatively strong, with O...O donor–acceptor distances of 2.6262 (17) and 2.6240 (19) Å for the Al and Ga compounds, respectively. The two diarsenate compounds are representatives of the NaAlAs2O7structure type, characterized by an anionic framework topology built ofM3+O6octahedra (M= Al, Ga) sharing corners with diarsenate groups, andM+cations (M= Ag) hosted in the voids of the framework. Both structures are characterized by a staggered conformation of the As2O7groups.

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

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

Thermal-induced transformation of glutamic acid to pyroglutamic acid and self-cocrystallization: a charge–density analysis

2022 ◽  
Vol 78 (2) ◽  
Author(s):  
Sehrish Akram ◽  
Arshad Mehmood ◽  
Sajida Noureen ◽  
Maqsood Ahmed
Keyword(s):  
Hydrogen Bonds ◽  
Glutamic Acid ◽  
Single Crystal ◽  
Diffraction Data ◽  
Density Functional ◽  
Quantitative Estimation ◽  
Topological Analysis ◽  
Pyroglutamic Acid ◽  
X Ray Diffraction ◽  
X Ray

Thermal-induced transformation of glutamic acid to pyroglutamic acid is well known. However, confusion remains over the exact temperature at which this happens. Moreover, no diffraction data are available to support the transition. In this article, we make a systematic investigation involving thermal analysis, hot-stage microscopy and single-crystal X-ray diffraction to study a one-pot thermal transition of glutamic acid to pyroglutamic acid and subsequent self-cocrystallization between the product (hydrated pyroglutamic acid) and the unreacted precursor (glutamic acid). The melt upon cooling gave a robust cocrystal, namely, glutamic acid–pyroglutamic acid–water (1/1/1), C5H7NO3·C5H9NO4·H2O, whose structure has been elucidated from single-crystal X-ray diffraction data collected at room temperature. A three-dimensional network of strong hydrogen bonds has been found. A Hirshfeld surface analysis was carried out to make a quantitative estimation of the intermolecular interactions. In order to gain insight into the strength and stability of the cocrystal, the transferability principle was utilized to make a topological analysis and to study the electron-density-derived properties. The transferred model has been found to be superior to the classical independent atom model (IAM). The experimental results have been compared with results from a multipolar refinement carried out using theoretical structure factors generated from density functional theory (DFT) calculations. Very strong classical hydrogen bonds drive the cocrystallization and lend stability to the resulting cocrystal. Important conclusions have been drawn about this transition.

scholarly journals Redetermination of Sr2PdO3 from single-crystal X-ray data

2019 ◽  
Vol 75 (1) ◽  
pp. 30-32
Author(s):  
Gohil S. Thakur ◽  
Hans Reuter ◽  
Claudia Felser ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Structure Type ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters

The crystal structure redetermination of Sr2PdO3 (distrontium palladium trioxide) was carried out using high-quality single-crystal X-ray data. The Sr2PdO3 structure has been described previously in at least three reports [Wasel-Nielen & Hoppe (1970). Z. Anorg. Allg. Chem. 375, 209–213; Muller & Roy (1971). Adv. Chem. Ser. 98, 28–38; Nagata et al. (2002). J. Alloys Compd. 346, 50–56], all based on powder X-ray diffraction data. The current structure refinement of Sr2PdO3, as compared to previous powder data refinements, leads to more precise cell parameters and fractional coordinates, together with anisotropic displacement parameters for all sites. The compound is confirmed to have the orthorhombic Sr2CuO3 structure type (space group Immm) as reported previously. The structure consists of infinite chains of corner-sharing PdO4 plaquettes interspersed by SrII atoms. A brief comparison of Sr2PdO3 with the related K2NiF4 structure type is given.

scholarly journals Redetermination of the crystal structure of RhPb2 from single-crystal X-ray diffraction data, revealing a rhodium deficiency

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Takashi Mochiku ◽  
Yoshitaka Matsushita ◽  
Nikola Subotić ◽  
Takanari Kashiwagi ◽  
Kazuo Kadowaki
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Structure Type ◽  
Site Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Anisotropic Displacement Parameters ◽  
Slight Deficiency

RhPb2 (rhodium dilead) is a superconductor crystallizing in the CuAl2 structure type (space group I4/mcm). The Rh and Pb atoms are located at the 4a (site symmetry 422) and 8h (m.2m) sites, respectively. The crystal structure is composed of [RhPb8] antiprisms, which share their square faces along the c axis and the edges in the direction perpendicular to the c axis. We have succeeded in growing single crystals of RhPb2 and have re-determined the crystal structure on basis of single-crystal X-ray diffraction data. In comparison with the previous structure studies using powder X-ray diffraction data [Wallbaum (1943). Z. Metallkd. 35, 218–221; Havinga et al. (1972). J. Less-Common Met. 27, 169–186], the current structure analysis of RhPb2 leads to more precise unit-cell parameters and fractional coordinates, together with anisotropic displacement parameters for the two atoms. In addition and likewise different from the previous studies, we have found a slight deficiency of Rh in RhPb2, leading to a refined formula of Rh0.950 (9)Pb2.

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

IUCrData ◽  
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].

Structure Refinement of CePtSi and Hydrogenation Behavior of CePdGe, CePtSi and CePtGe

2007 ◽  
Vol 62 (4) ◽  
pp. 613-616 ◽  
Author(s):  
Wilfried Hermes ◽  
Ute Ch. Rodewald ◽  
Bernard Chevalier ◽  
Rainer Pötgena
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Subsequent Annealing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydride Formation ◽  
Arc Melting ◽  
Cerium Compounds

The intermetallic cerium compounds CePdGe, CePtSi, and CePtGe were synthesized from the elements by arc-melting and subsequent annealing. The structure of CePtSi was refined from single crystal X-ray diffraction data: LaPtSi-type (ordered α-ThSi2 version), 141md, a = 419.6(1) and c = 1450.0(5) pm, wR2 = 0.0490, 362 F2 values and 16 variables. The Pt-Si distances within the three-dimensional [PtSi] network are 242 pm, indicating strong Pt-Si interactions. Hydrogenation of the three compounds at 623 K and 4 MPa H2 gave no indication for hydride formation.

M3+(H2AsO4)(H2As2O7) (M3+= Al, Ga) and In2(H2AsO4)2(H2As2O7)2: a new layer structure type and a new framework structure type containing the rare H2As2O72−group

2017 ◽  
Vol 73 (8) ◽  
pp. 600-608 ◽  
Author(s):  
Karolina Schwendtner ◽  
Uwe Kolitsch
Keyword(s):  
Hydrogen Bonds ◽  
Room Temperature ◽  
Layer Structure ◽  
Structure Type ◽  
Three Dimensions ◽  
Framework Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Third ◽  
New Framework

The crystal structures of hydrothermally synthesized aluminium dihydrogen arsenate(V) dihydrogen diarsenate(V), Al(H2AsO4)(H2As2O7), gallium dihydrogen arsenate(V) dihydrogen diarsenate(V), Ga(H2AsO4)(H2As2O7), and diindium bis[dihydrogen arsenate(V)] bis[dihydrogen diarsenate(V)], In2(H2AsO4)2(H2As2O7)2, were determined from single-crystal X-ray diffraction data collected at room temperature. The first two compounds are representatives of a novel sheet structure type, whereas the third compound crystallizes in a novel framework structure. In all three structures, the basic building units areM3+O6octahedra (M= Al, Ga, In) that are connectedviaone H2AsO4−and two H2As2O72−groups into chains, and furtherviaH2As2O72−groups into layers. In Al/Ga(H2AsO4)(H2As2O7), these layers are interconnected by weak-to-medium–strong hydrogen bonds. In In2(H2AsO4)2(H2As2O7)2, the H2As2O72−groups link the chains in three dimensions, thus creating a framework topology, which is reinforced by weak-to-medium–strong hydrogen bonds. The three title arsenates represent the first compounds containing both H2AsO4−and H2As2O72−groups.

scholarly journals Reinvestigation of trilithium divanadium(III) tris(orthophosphate), Li3V2(PO4)3, based on single-crystal X-ray data

2013 ◽  
Vol 69 (2) ◽  
pp. i11-i12 ◽  
Author(s):  
Yongho Kee ◽  
Hoseop Yun
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Title Compound ◽  
Three Dimensional ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Charge Balance ◽  
X Ray ◽  
Anisotropic Displacement Parameters

The structure of Li3V2(PO4)3has been reinvestigated from single-crystal X-ray data. Although the results of the previous studies (all based on powder diffraction data) are comparable with our redetermination, all atoms were refined with anisotropic displacement parameters in the current study, and the resulting bond lengths are more accurate than those determined from powder diffraction data. The title compound adopts the Li3Fe2(PO4)3structure type. The structure is composed of VO6octahedra and PO4tetrahedra by sharing O atoms to form the three-dimensional anionic framework∞3[V2(PO4)3]3−. The positions of the Li+ions in the empty channels can vary depending on the synthetic conditions. Bond-valence-sum calculations showed structures that are similar to the results of the present study seem to be more stable compared with others. The classical charge balance of the title compound can be represented as [Li+]3[V3+]2[P5+]3[O2−]12.

Description of Ba1 + x Ni x Rh1 − x O3 with x = 0.1170 (5) in superspace: modulated composite versus modulated-layer structure

2006 ◽  
Vol 62 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Andreas Schönleber ◽  
F. Javier Zúñiga ◽  
J. Manuel Perez-Mato ◽  
Jacques Darriet ◽  
Hans-Conrad zur Loye
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Room Temperature ◽  
Layer Structure ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray

The structure of the compound Ba1 + x Ni x Rh1 − x O3 [x = 0.1170 (5)] has been analyzed at room temperature within the (3 + 1)-dimensional superspace approach using single-crystal X-ray diffraction data. Two different models are presented, the compound is refined as modulated composite as well as modulated-layer structure. In both models discontinuous atomic domains are applied to describe the structural modulations. While the first approach stresses the pseudo-one-dimensional constitution, the latter highlights the layered character of these structures.

The crystal structure of a simple enol formed in a single-crystal-to-single-crystal enolene rearrangement

2004 ◽  
Vol 82 (2) ◽  
pp. 301-305 ◽  
Author(s):  
Kenneth CW Chong ◽  
Brian O Patrick ◽  
John R Scheffer
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
Room Temperature ◽  
Thermal Reaction ◽  
Thermal Rearrangement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phenyl Ketone

When crystals of 9-tricyclo[4.4.1.0]undecalyl-4-(carbomethoxy)phenyl ketone (1) were allowed to stand in the dark for extended periods of time at room temperature, the compound underwent a thermal reaction — the enolene rearrangement — to afford enol 2. The crystals remained transparent and appeared unchanged in shape as the reaction proceeded. X-ray diffraction data were collected on single crystals containing 17%, 25%, 66%, and 100% of the enol. The crystal structure of a simple enol was obtained via this novel single-crystal-to-single-crystal enolene rearrangement.Key words: single crystal, thermal, rearrangement, enol, enolene.

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