trans-Bis(O-ethylxanthato)bis(triphenylphosphine)ruthenium(III) hexafluorophosphate monohydrate

2006 ◽  
Vol 62 (5) ◽  
pp. m1077-m1078
Author(s):  
Yuko Ohuchi ◽  
Kyoko Noda ◽  
Takayoshi Suzuki ◽  
Kazuo Kashiwabara ◽  
Hideo D. Takagi
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Complex Cation ◽  
Orthorhombic Crystal ◽  
Monoclinic Crystal ◽  
Monoclinic Crystal Structure

In the monoclinic crystal structure of the title compound, trans-[Ru(C3H5OS2)2(C18H15P)2]PF6·H2O, the structure of the RuIII complex cation is very similar to that in the orthorhombic crystal of the nonhydrated complex [Noda, Ohuchi, Hashimoto, Fujiki, Itoh, Iwatsuki, Noda, Suzuki, Kashiwabara & Takagi (2006), Inorg. Chem. 45, 1349–1355]. In the present crystal structure, the P—Ru—P bond axes of the complex cations are aligned parallel to the [101] direction.

Electron density, disorder and polymorphism: high-resolution diffraction studies of the highly polymorphic neuralgic drug carbamazepine

2016 ◽  
Vol 72 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Ioana Sovago ◽  
Matthias J. Gutmann ◽  
Hans Martin Senn ◽  
Lynne H. Thomas ◽  
Chick C. Wilson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Diffraction Data ◽  
Structural Formula ◽  
Orthorhombic Crystal ◽  
Monoclinic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Monoclinic Crystal Structure

Analysis of neutron and high-resolution X-ray diffraction data on form (III) of carbamazepine at 100 K using the atoms in molecules (AIM) topological approach afforded excellent agreement between the experimental results and theoretical densities from the optimized gas-phase structure and from multipole modelling of static theoretical structure factors. The charge density analysis provides experimental confirmation of the partially localized π-bonding suggested by the conventional structural formula, but the evidence for any significant C—N π bonding is not strong. Hirshfeld atom refinement (HAR) gives H atom positional and anisotropic displacement parameters that agree very well with the neutron parameters. X-ray and neutron diffraction data on the dihydrate of carbemazepine strongly indicate a disordered orthorhombic crystal structure in the space groupCmca, rather than a monoclinic crystal structure in space groupP21/c. This disorder in the dihydrate structure has implications for both experimental and theoretical studies of polymorphism.

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.

Preparation, Crystal Structure, and Properties of the Lanthanoid Carbides Ln4C7 with Ln = Ho, Er, Tm, and Lu

1996 ◽  
Vol 51 (5) ◽  
pp. 646-654 ◽  
Author(s):  
Ralf Czekalla ◽  
Wolfgang Jeitschko ◽  
Rolf-Dieter Hoffmann ◽  
Helmut Rabeneck
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Magnetic Ordering ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Neutron Powder Diffraction Data ◽  
Monoclinic Crystal Structure ◽  
Arc Melting ◽  
Structure Factors ◽  
Hydrolysis Of

The isotypic carbides Ln4C7 (Ln = Ho, Er, Tm, Lu) were prepared by arc-melting of the elemental components, followed by annealing at 1300 °C. The positions of the metal and of some carbon atoms of the monoclinic crystal structure of LU4C7 were determined from X-ray powder data, and the last carbon positions were found and refined from neutron powder diffraction data: P21/c, a = 360.4(1), b = 1351.4(3), c = 629.0(2) pm, β = 104.97(2)°, Z = 2, R = 0.026 for 429 structure factors and 15 positional parameters. The structure contains isolated carbon atoms with octahedral lutetium coordination and linear C3-units, with C-C bond lengths of 132(1) and 135(1) pm. This carbide may therefore be considered as derived from methane and propadiene. The hydrolysis of LU4C7 with distilled water yields mainly methane and propine, while the hydrolyses of the corresponding holmium and erbium carbides resulted in relatively large amounts of saturated and unsaturated C2-hydrocarbons in addition to the expected products methane and propine. The structure comprises two-dimensionally infinite NaCl-type building elements, which are separated by the C3-units. It may be described as a stacking variant of a previously reported structure of HO4C7, now designated as the a-modification. The Lu4C7-type β -modification was obtained at higher temperatures. Its structure was refined by the Rietveld method from X-ray powder data to a residual R = 0.037 for 320 F values and 15 positional parameters. Lu4C7 is Pauli paramagnetic; β -HO4C7 and Er4C7 show Curie-Weiss behavior with magnetic ordering temperatures of less than 20 K.

Crystal chemistry of inorganic compounds based on chains of oxocentered tetrahedra III. Crystal structure of georgbokiite, Cu5O2(SeO3)2Cl21

1999 ◽  
Vol 214 (3) ◽  
Author(s):  
S. V. Krivovichev ◽  
R. R. Shuvalov ◽  
T. F. Semenova ◽  
S. K. Filatov
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Crystal Chemistry ◽  
Inorganic Compounds ◽  
New Mineral ◽  
Monoclinic Crystal ◽  
Monoclinic Crystal Structure

AbstractThe monoclinic crystal structure of georgbokiite, a new mineral with the chemical composition Cu

scholarly journals The monoclinic crystal structure form of bacterioferritin fromE. coli

1996 ◽  
Vol 52 (a1) ◽  
pp. C177-C177
Author(s):  
M. Hospital ◽  
A. Dautant ◽  
J. Yariv ◽  
G. Précigoux ◽  
A. J. Kalb (Gilboa) ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Form ◽  
Monoclinic Crystal ◽  
Monoclinic Crystal Structure

scholarly journals A new crystalline form of αβ-D-lactose prepared by oven drying a concentrated aqueous solution of D-lactose

2019 ◽  
Vol 75 (7) ◽  
pp. 904-909 ◽  
Author(s):  
Daniel Nicholls ◽  
Carole Elleman ◽  
Norman Shankland ◽  
Kenneth Shankland
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Three Dimensional ◽  
Crystalline Form ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Monoclinic Crystal Structure ◽  
High Degree ◽  
Triclinic Form

A new crystalline form of αβ-D-lactose (C12H22O11) has been prepared by the rapid drying of an approximately 40% w/v syrup of D-lactose. Initially identified from its novel powder X-ray diffraction pattern, the monoclinic crystal structure was solved from a microcrystal recovered from the generally polycrystalline mixed-phase residue obtained at the end of the drying step. This is the second crystalline form of αβ-D-lactose to be identified and it has a high degree of structural three-dimensional similarity to the previously identified triclinic form.

Novel aluminophosphate Na6[Al3P5O20] with the original microporous crystal structure established in the study of a pseudomerohedric microtwin

2021 ◽  
Vol 77 (2) ◽  
pp. 232-240
Author(s):  
Olga V. Yakubovich ◽  
Galina V. Kiriukhina ◽  
Anatoliy S. Volkov ◽  
Olga V. Dimitrova ◽  
Elena Yu. Borovikova
Keyword(s):  
Crystal Structure ◽  
Unit Cell Parameters ◽  
Monoclinic Crystal ◽  
Cell Parameters ◽  
Monoclinic Crystal Structure ◽  
Generalized Framework ◽  
Microporous Zeolite ◽  
Phosphate Groups ◽  
Framework Density

The synthesis and characterization of a new aluminophosphate, Na6[Al3P5O20], obtained as single crystals in the same experiment together with Cl-sodalite, Na8[Al6Si6O24]Cl2, is reported. Na6[Al3P5O20], with a strongly pseudo-orthorhombic lattice, is described by the monoclinic crystal structure established in the study of a pseudomerohedric microtwin. The design of Na6[Al3P5O20] can be interpreted as an alternative to sodalite, with a monoclinic (pseudo-orthorhombic) 2×4×1 super-structure and unit-cell parameters multiples of those of sodalite: a ≃ 2a s, b ≃ 4b s and c ≃ c s. The triperiodic framework is built by AlO6, AlO4 and PO4 polyhedra having vertex-bridging contacts. While all the oxygen vertices of the Al-centred octahedra and tetrahedra are shared with phosphate groups, some of the PO4 tetrahedra remain `pendant', e.g. containing vertices not shared with other polyhedra of the aluminophosphate construction. Na atoms occupy framework channels and cavities surrounded by eight-, six- and four-membered windows with maximal effective pore widths of 4.86 × 3.24 and 4.31 × 3.18 Å. The generalized framework density is equal to 19.8, which means that the compound may be classified as a microporous zeolite. The Na6[Al3P5O20] crystal structure is discussed as being formed from octahedral rods arranged in two perpendicular directions, similar to the rods elongated in one direction in the NASICON-type compounds, which have been intensively investigated as promising materials for batteries. Analogous properties can be expected for phases with a modified composition of the Na6Al3P5O20 topology, where the Al atoms at the centres of octahedra are replaced by Fe, V or Cr.

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