A distorted tetrahedral copper(II) complex: 1,2-bis(diphenylphosphineoxido)ethane copper(II) chloride

1969 ◽  
Vol 47 (6) ◽  
pp. 1093-1094 ◽  
Author(s):  
M. Mathew ◽  
Gus J. Palenik
Keyword(s):  
Crystal Structure ◽  
Structural Determination ◽  
X Ray Diffraction ◽  
Tetrahedral Symmetry ◽  
X Ray ◽  
The Ideal

The crystal structure of 1,2-bis(diphenylphosphineoxido)ethane copper(II) chloride has been determined by X-ray diffraction techniques. The compound is the first structural determination of a CuCl2–phosphineoxide adduct and exhibits some very large distortions from the ideal tetrahedral symmetry. The Cl—Cu—O angle is 140.2° and the Cu—Cl distance of 2.195 Å is shorter than in other CuCl2 complexes.

The Crystal-Structure of Tetraphenylarsonium Tetrachlorooxotechnetate(V)

1989 ◽  
Vol 42 (7) ◽  
pp. 1155 ◽  
Author(s):  
J Baldas ◽  
SF Colmanet
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Structural Determination ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal structure of [AsPh4] [TcOCl4] (1) has been determined by X-ray diffraction. Crystals are tetragonal, space group P4/n, a 12.664(1), c 7.822(1) � , Z = 2. Refinement based on 912 data measured with Cu Ka radiation converged with R 0.059. The structure consists of discrete [AsPh4]+ cations and [TcOCl4]- anions with the technetium atom in a square-pyramidal environment. In contrast to an earlier structural determination of the [TcOCl]-anion in [N(PPh3)2] [TcOCl4], the [TcOCl4]-anion in (1) possesses ideal symmetry. The Tc =O bond length is 1.593(8) � with Tc -CI 2.309(2) �.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

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.

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].

Determination of the Crystal Structure and Redefinition of Tsugaruite, Pb28As15S50Cl, the First Lead-Arsenic Chloro-Sulfosalt

2020 ◽  
Author(s):  
Cristian Biagioni ◽  
Luca Bindi ◽  
Koichi Momma ◽  
Ritsuro Miyawaki ◽  
Yoshitaka Matsushita ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Specific Position ◽  
Actual Classification ◽  
Aomori Prefecture

Abstract Tsugaruite was originally defined as a lead-arsenic sulfosalt from the Yunosawa mine, Aomori Prefecture, Japan. Until recently its crystal structure remained unsolved and its actual classification in the sulfosalt realm was unknown. Here the refinement of the crystal structure of tsugaruite using single-crystal X-ray diffraction data is reported. The mineral is orthorhombic, space group P2nn, with unit-cell parameters a = 8.0774(10), b = 15.1772(16), c = 38.129(4) Å, V = 4674.3(9) Å3, in agreement with previous studies. The solution of the crystal structure of this mineral revealed Cl occupying a specific position. Chlorine was thus sought and found using the electron microprobe; the average of six spot analyses gave (in wt.%): Pb 68.04, As 12.83, S 18.29, Cl 0.63, total 99.80. The empirical formula, calculated on the basis of Pb + As = 43 atoms per formula unit, is Pb28.26As14.74S49.08Cl1.52. Tsugaruite is an N = 4 plesiotypic derivative of the homologous series of Pb-Sb chloro-sulfosalts having the general formula Pb(2+2N)(Sb,Pb)(2+2N)S(2+2N)(S,Cl)(4+2N)ClN. It has a Cl/(Cl + S) atomic ratio close to that of other known Pb-Sb chloro-sulfosalts (pillaite, pellouxite) and slightly higher than that of dadsonite.

Structure determination of fatty acid ester biofuels via in situ cryocrystallisation and single crystal X-ray diffraction

CrystEngComm ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Siriyara Jagannatha Prathapa ◽  
Cara Slabbert ◽  
Manuel A. Fernandes ◽  
Andreas Lemmerer
Keyword(s):  
Crystal Structure ◽  
Fatty Acid ◽  
Fatty Acid Ester ◽  
Structure Determination ◽  
Homologous Series ◽  
Methyl Esters ◽  
X Ray Diffraction ◽  
X Ray

In situ cryocrystallisation enabled the crystal structure determination of a homologous series of low-melting n-alkyl methyl esters Cn−1H2n+1CO2CH3.

The crystal structure of gersdorffite (III), a distorted and disordered pyrite structure

1968 ◽  
Vol 36 (283) ◽  
pp. 940-947 ◽  
Author(s):  
P. Bayliss ◽  
N. C. Stephenson
Keyword(s):  
Crystal Structure ◽  
Metal Atom ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Partially Ordered ◽  
The Ideal

SummaryThe crystal structure of gersdorffite (III) has been examined with three-dimensional Weissenberg X-ray diffraction data. The unit cell is isometric with a 5·6849 ± 0·0003 Å, space group PI, and four formula units per cell. This structure has the sulphur and arsenic atoms equally distributed over the non-metal atom sites of pyrite. All atoms show significant random displacements from the ideal pyrite positions to produce triclinic symmetry, which serves to distinguish this mineral from a disordered cubic gersdorffite (II) and a partially ordered cubic gersdorffite (I). Factors responsible for the atomic distortions are discussed.

scholarly journals Fogoite-(Y), Na3Ca2Y2Ti(Si2O7)2OF3, a Group I TS-block mineral from the Lagoa do Fogo, the Fogo volcano, São Miguel Island, the Azores: Description and crystal structure

2017 ◽  
Vol 81 (2) ◽  
pp. 369-381 ◽  
Author(s):  
F. Cámara ◽  
E. Sokolova ◽  
Y. A. Abdu ◽  
F. C. Hawthorne ◽  
T. Charrier ◽  
...  
Keyword(s):  
Crystal Structure ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Titanium Silicate ◽  
Triclinic Space Group ◽  
X Ray ◽  
Group I ◽  
Mohs Hardness ◽  
Fogo Volcano ◽  
The Ideal

AbstractFogoite-(Y), Na3Ca2Y2Ti(Si2O7)2OF3, is a new mineral from the Lagoa do Fogo, São Miguel Island, the Azores. It occurs in cavities as highly elongated (on [001]) prisms, up to 2000 μm long and 50 μm× 50 μm in cross-section, associated with sanidine, astrophyllite, fluornatropyrochlore, ferrokentbrooksite, quartz and ferro-katophorite. Crystals are generally transparent and colourless, with vitreous lustre, occasionally creamy white. Fogoite-(Y) has a white streak, splintery fracture and very good {100} cleavage. Mohs hardness is ∼5. Dcalc. = 3.523 g/cm3. It is biaxial (+) with refractive indices (λ = 590 nm) α = 1.686(2), β = 1.690(2), γ = 1.702(5); 2Vmeas. = 57(1)° and 2Vcalc. = 60°. It is nonpleochroic. Fogoite-(Y) is triclinic, space group P1, a = 9.575(6), b = 5.685(4), c = 7.279(5) Å, α = 89.985(6), β = 100.933(4), γ = 101.300(5)°, V = 381.2 (7) Å3. The six strongest reflections in the powder X-ray diffraction data [d (Å), I, (hkl)] are: 2.954, 100, (1̄1̄2, 3̄10); 3.069, 42, (300, 01̄2); 2.486, 24, (310, 21̄2); 3.960, 23, (1̄1̄1, 2̄10); 2.626, 21, (2̄20); 1.820, 20, (1̄04). Electron microprobe analysis gave the following empirical formula calculated on 18 (O + F) (Na2.74Mn0.15)∑2.89Ca2[Y1.21(La0.01Ce0.03Nd0.03Sm0.02Gd0.08Dy0.08Er0.05Yb0.04Lu0.01)∑0.35Mn0.16Zr0.11Na0.09Fe0.072+Ca0.01]∑2(Ti0.76Nb0.23Ta0.01)∑1(Si4.03O14)O1.12F2.88, Z = 1. The crystal structure was refined on a twinnedcrystal to R1 = 2.81% on the basis of 2157 unique reflections (Fo > 4σFo) and is a framework of TS (Titanium Silicate) blocks, which consist of HOH sheets (H – heteropolyhedral, O – octahedral) parallel to (100). In the O sheet, the the [6]MO(1) site is occupied mainly by Ti, <MO(1)–ϕ> = 1.980 Å, and the [6]MO(2) and [6]MO(3) sites are occupied by Na and Na plus minor Mn, <MO(2)–ϕ>= 2.490 Å and <MO(3)–ϕ> = 2.378 Å. In the H sheet, the two [4]Si sites are occupied by Si, with <Si–O> = 1.623 Å; the [6]MH site is occupied by Y and rare-earth elements (Y > REE), with minor Mn, Zr, Na, Fe2+ and Ca, <MH–ϕ> = 2.271 Å and the [6]AP site is occupied by Ca, <AP–ϕ> = 2.416 Å. The MH and AP octahedra and Si2O7 groups constitute the H sheet. The ideal compositions of the O and two H sheets are Na3Ti(OF)F2 and Y2Ca2(Si2O7)2 apfu. Fogoite-(Y) is isostructural with götzenite and hainite. The mineral is named after the type locality, the Fogo volcano in the Azores.

Ideal and Real Structure of Ti5O4(PO4)4: X-ray and HRTEM Investigations

1998 ◽  
Vol 54 (6) ◽  
pp. 722-731 ◽  
Author(s):  
F. Reinauer ◽  
R. Glaum
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Structure Refinement ◽  
Ideal Structure ◽  
Crystal Data ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Ideal

The crystal structure of pentatitanium tetraoxide tetrakis(phosphate), Ti5O4(PO4)4, has been determined and refined from X-ray diffraction single-crystal data [P212121 (No. 19), Z = 4, a = 12.8417 (12), b = 14.4195 (13), c = 7.4622 (9) Å (from Guinier photographs); conventional residual R 1 = 0.042 for 2556 Fo > 4σ(Fo ), R 1 = 0.057 for all 3276 independent reflections; 282 parameters; 29 atoms in the asymmetric unit of the ideal structure]. The structure is closely related to those of β-Fe2O(PO4)-type phosphates and synthetic lipscombite, Fe3(PO4)4(OH). While these consist of infinite chains of face-sharing MO6 octahedra, in pentatitanium tetraoxide tetrakis(phosphate) only five-eighths of the octahedral voids are occupied according to □3Ti5O4(PO4)4. Four of the five independent Ti4+O6 show high radial distortion [1.72 ≤ d(Ti−O) ≤ 2.39 Å] and a typical 1 + 4 + 1 distance distribution. The fifth Ti4+O6 is an almost regular octahedron [1.91 ≤ d(Ti−O) ≤ 1.98 Å]. Partial disorder of Ti4+ over the available octahedral voids is revealed by the X-ray structure refinement. High-resolution transmission electron microscopy (HRTEM) investigations confirm this result.

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