Darstellung und Kristallstruktur von Na4GeSe4: Ein neues ortho-Selenogermanat(IV)

1985 ◽  
Vol 40 (7) ◽  
pp. 878-882 ◽  
Author(s):  
Kurt O. Klepp
Keyword(s):  
Crystal Structure ◽  
Orthorhombic Structure ◽  
Tetrahedral Geometry ◽  
Space Group ◽  
Bond Lengths ◽  
Structure Space ◽  
Mixed Cation ◽  
The Mean

Abstract Na4GeSe4 was obtained from a stoichiometric melt of Na2Se, Ge and Se at 750 °C. It crystallizes with a new orthorhombic structure, space group Pnma, with a = 28.518(8), b - 9.447(5), c = 7.128(2) Å , Z = 8. The crystal structure was refined to a conventional R of 0.074 for 1236 reflections with I > 3 σ (I) (diffractometer data). It is characterized by discrete GeSe44--anions with almost regular tetrahedral geometry. Two independent anions appear in the structure, the mean Ge - Se-bond lengths are 2.345 and 2.353 Å, resp. The Na+-ions are coordinated to 4 -6 chalcogen atoms in the range 2.88-3.28 Å. The structure is composed of mixed cation-anion-slabs, 2∞ [Na2(GeSe4)2-], which run parallel to the bc-plane and are separated from each other by corrugated 36-layers of Na+-ions.

The crystal structure of p-diethylaminobenzenediazonium hexafluorophosphate

1985 ◽  
Vol 63 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Richard G. Ball ◽  
Richard MacLeod Elofson
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Triple Bond ◽  
Direct Methods ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean ◽  
Least Squares Techniques ◽  
Diazo Group

p-Diethylaminobenzenediazonium hexafluorophosphate, C10H14N3+•PF6−, crystallized in space group [Formula: see text] with a = 12.105(4), b = 12.340(5), c = 10.439(4) Å, α = 96.53(3), β = 104.11(3), γ = 64.44(3)°, and Z = 4. The structure was solved using direct methods and refined with full-matrix least-squares techniques on F, to a final R of 0.054 for 1917 reflections with F2 > 3σ(F2). The mean bond lengths for the diazo group are: N—N 1.096(6); C—N 1.357(7) Å. The geometry of the molecule is discussed in terms of the possible resonance forms and it is shown to be consistent with a form in which the N—N triple bond is essentially intact and the aminobenzene moiety has "quinoidal" character.

scholarly journals Crystal structure of CaK2As2O7 and CdK2P2O7

1976 ◽  
Vol 54 (21) ◽  
pp. 3319-3324 ◽  
Author(s):  
Romolo Faggiani ◽  
Crispin Calvo
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Coordination Sphere ◽  
Divalent Cations ◽  
Lattice Parameters ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean ◽  
Oxygen Atoms

Crystals of CaK2As2O7 and CdK2P2O7, both grown from the melt, are monoclinic with Z = 4. The lattice parameters are a = 9.222(6), b = 5.835(3), c = 14.698(10) Å, β = 105.84(5)° with space group P21/c for the diarsenate and a = 9.737(2), b = 5.548(1), c = 12.766(2) Å, β = 106.50(2)° with space group C2/c for the diphosphate. The structures were refined by full-matrix least-squares methods utilizing 2070 reflections (R = 0.056) for the diarsenate and 1145 reflections (R = 0.067) for the diphosphate. Both structures contain pseudo-hexagonally packed anions, in staggered configurations, forming layers with the divalent cations in six coordinate sites between the layers. The average M—O bond lengths are 2.342 and 2.290 Å for M = Ca and Cd respectively. The K ion has nine oxygen atoms with mean K—O bond lengths of 2.943 and 3.020 Å in the diarsenate in the coordination sphere. The mean of the ten shortest K—O is 2.939 Å in the diphosphate.

Komplexe Chalkogenide der IVa Metalle mit niedrigdimensionalen anionischen Partialstrukturen. Darstellung und Kristallstruktur von K2ZrTe3 und Rb2ZrTe3 / Complex Chalcogenides of the IVa Metals with Low Dimensional Anionic Partial Structures. Preparation and Crystal Structures of K2ZrTe3 and Rb2ZrTe3

1999 ◽  
Vol 54 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Kurt O. Klepp ◽  
Andreas Kolb
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Alkali Cations ◽  
Space Group ◽  
Bond Lengths ◽  
Partial Structures ◽  
Distorted Octahedral ◽  
New Type ◽  
The Mean ◽  
Low Dimensional

The isostructural compounds K2ZrTe3 and Rb2ZrTe3 were obtained at 1000°C by reacting K2Te and Rb2Te with stoichiometric amounts of Zr and Te. The compounds are monoclinic, mP24, space group P21/c, Z = 4 with a = 9.089(3), b = 14.148(4), c = 6.986(3) Å, β = 105.90( 1)° and a = 9.735(4), b = 14.300(7), c = 6.952(8) Å, β = 108.61(2)°, respectively. The crystal structure was determined from diffractometer data and refined to R = 0.030 for 1452 Fo's for K2ZrTe3 and R = 0.038 for 1131 Fo's for Rb2ZrTe3. The crystal structure is of a new type, characterized by infinite anionic chains, 1∞-[ZrTe3]2- built up by octahedra sharing opposite faces which run along [001]. The mean Zr-Te bond lengths are 2.921 and 2.920 Å, respectively. The alkali cations separating the chains are characterized by two different - distorted octahedral and pentagonal bipyramidal - chalcogen environments.

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.

Syntheses and vibrational spectra of some tris(alkanethiolato)mercurate(II) complexes, and crystal structure of the Hexakis(methanethiolato)dimercurate(II) dianion

1984 ◽  
Vol 37 (8) ◽  
pp. 1607 ◽  
Author(s):  
GA Bowmaker ◽  
IG Dance ◽  
BC Dobson ◽  
DA Rogers
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Vibrational Spectra ◽  
Crystal Data ◽  
Tetrahedral Geometry ◽  
Space Group ◽  
Spectroscopic Evidence ◽  
Distorted Tetrahedral Geometry ◽  
Complex Anions

The complexes [cation] [Hg(SR)3](R = Me, cation = Et4N+; R = But, cation = Et4N+, Bu4N+, [N(Ph3P)2]+) have been prepared. The crystal structure of the methanethiolate complex shows that it contains centrosymmetric dinuclear anions [(MeS)2Hg(�-SMe)2Hg(SMe)2]2- with distorted tetrahedral geometry about the mercury atoms. Vibrational spectroscopic evidence suggests that this complex dissociates on dissolution in ethanol to give mononuclear [Hg(SMe)3]- species. The ButS- complexes appear to exist as mononuclear [Hg(SBut)3]- species both in the solid state and in solution. The metal-sulfur stretching frequencies are assigned for all of the complexes studied, and the vibrational spectra are discussed in terms of the structures of the complex anions involved. Crystal data for [(C2H5)4N]2Hg2(SCH3)6 : a 8.656(5), b gS130(6), c 12.368(8) �; α 102.16(4), β 105.51(4), γ 105.29(4)�; space group P1, Z 1, R 0.034, Rw 0.042.

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.

scholarly journals Über die Reaktion von Wolframhexachlorid mit Se4N2; Kristallstruktur von PPh4[WCl5(NSeCl)] / On the Reaction of Tungsten Hexachloride with Se4N2; Crystal Structure of PPh4[WCl5(NSeCl)]

1991 ◽  
Vol 46 (12) ◽  
pp. 1625-1628 ◽  
Author(s):  
Stefan Vogler ◽  
Werner Massa ◽  
Kurt Dehnicke
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Structure Determination ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Tetraphenylphosphonium Chloride ◽  
Tungsten Hexachloride

The reaction of tungsten hexachloride with Se4N2 leads to [WCl4(NSeCl)]2, which reacts with pyridine to form [WCl4(NSeCl)Py], and with tetraphenylphosphonium chloride to form PPh4[WCl5(NSeCl)], which was characterized by an X-ray structure determination. Space group P21, Z = 2, 1657 observed unique reflections, R = 0.074, wR = 0.061. Lattice dimensions at —80 C: a = 710.7(1), b = 2217.9(4), c = 953.6(2) pm; β = 111.93(3) . The [WCl5(NSeCl)]- ion possesses an almost linear WNSe group with bond lengths WN = 188 pm, corresponding to a double bond, and NSe = 200 pm.

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.

Synthesen und Kristallstrukturen von [PPh3Me]NO2 und [PPh3 Me]HCO2H2O / Syntheses and Crystal Structures of [PPh3Me]NO2 and [PPh3Me]HCO2H2O

1988 ◽  
Vol 43 (10) ◽  
pp. 1279-1284 ◽  
Author(s):  
Mervat El Essawi ◽  
H Gosmann ◽  
D Fenske ◽  
F Schmock ◽  
K Dehnicke
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Ir Spectra ◽  
Bond Angle ◽  
Water Molecules ◽  
Moist Air ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Structure Determinations

Triphenylmethylphosphonium nitrite and formate have been prepared by the reaction of [PPh3Me]I with silver nitrite, and lead formate, respectively, in aqueous solutions. [PPh3Me]NO2 (1) forms pale yellow crystals, and [PPh3Me]HCO2·H2O (2) forms white crystals. Both compounds are soluble in water, ethanol, and dichloromethane. In moist air 2 is hydrated to yield [PPh3Me]HCO2·2H2O (3). The compounds were characterized by their IR spectra, 1 and 2 also by X-ray crystal structure determinations.[PPh3Me]NO2 (1): space group P21/n, Z = 4, 2088 independent observed reflexions, R = 0.062. Lattice dimensions (20 °C): a = 914.7(3), b = 1887.5(9), c = 1080.0(4) pm, β = 110.29(3)°. The compound consists of PPh3Me+ ions and NO2- anions with bond lengths of 114.2(6) pm and a bond angle of 124.1(7)°. [PPh3Me]HCO2·H2O (2): space group P21/n, Z = 4, 2973 independent observed reflexions, R = 0.069. Lattice dimensions (-20 °C): a = 931(2), b = 1558(3), c = 1281(2) pm, β = 105.9(1)°. The compound consists of PPh3Me+ ions and formate anions which form centrosymmetric dimeric units [HCO2·H2O]22- through hydrogen bridges of the water molecules. Bond lengths CO 122.4(4) and 120.9(4) pm. bond angle OCO 129.9(4)°.

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