scholarly journals X-ray Crystallographic Study of Ranaconitine

2011 ◽  
Vol 6 (11) ◽  
pp. 1934578X1100601
Author(s):  
Yang Li ◽  
Jun-Hui Zhou ◽  
Gui-Jun Han ◽  
Min-Juan Wang ◽  
Wen-Ji Sun ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Diffraction Analysis ◽  
Critical Role ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Crystallographic Study ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The crystal structure of natural diterpenoid alkaloid ranaconitine isolated from Aconitum sinomontanum Nakai has been determined by single crystal X-ray diffraction analysis. The crystal presents a monoclinic system, space group C2 with Z = 4, unit cell dimensions a = 30.972(19) Å, b = 7.688(5) Å, and c = 19.632(12) Å. Moreover, the intermolecular O–H···O hydrogen bonds and weak π-π interactions play a critical role in expanding the dimensionality.

Structural study in the oligomethylene dithiobenzoate series, nDBS, where n, the number of methylene groups, is odd

1992 ◽  
Vol 70 (3) ◽  
pp. 900-909 ◽  
Author(s):  
Claude Leblanc ◽  
François Brisse
Keyword(s):  
Crystal Structure ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cells ◽  
Methylene Groups ◽  
Unit Cell Dimensions ◽  
Centrosymmetric Dimers

Model compounds of the poly(oligomethylene thioterephthalates) have been synthesized and characterized by X-ray diffraction analyses. The pink n-methylenedithiobenzoates, obtained for n = 3, 5, 7, and 9, all have a low melting point of about 320–330 K. They all crystallize in the monoclinic system, space group P21/c. The a and b unit cell dimensions vary little while the c dimension increases monotonically as n changes from 3 to 9. The crystal structure of the four compounds were established from low-temperature X-ray intensities. Except for the lengthening of the methylenic sequence, the four molecules studied here are isostructural. One of the thiobenzoate groups of the molecules is coplanar with all the methylenic carbons, while the other thiobenzoate group is at 90° from the above plane of atoms. The methylenic sequence has the same conformation. It may be described by g+(t)n, where n is the number of methylene groups. Thus, the four compounds belong to a crystallographically homologous series. The molecules form centrosymmetric "dimers," which, in turn, are herring-bone packed in their respective unit cells. In each "dimmer" two aromatic rings are across from one another while being mutually perpendicular. On the basis of the above results, one proposes three potentially acceptable structures for the parent poly(oligomethylene thioterephthalates). Keywords: dithiobenzoate, methylene sequence, crystal structure, poly(oligomethylene thioterephthalate).

scholarly journals The reaction of 3,5-diphenyl-1,2-dithiolium-4-olate with aniline: the crystal structure of 1-phenylimino-2-phenylamino-3-phenylindene

1987 ◽  
Vol 65 (12) ◽  
pp. 2830-2833 ◽  
Author(s):  
David M. McKinnon ◽  
Peter D. Clark ◽  
Robert O. Martin ◽  
Louis T. J. Delbaere ◽  
J. Wilson Quail
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

3,5-Diphenyl-1,2-dithiolium-4-olate (1) reacts with aniline to form 1-phenylimino-2-phenylamino-3-phenylindene (3a). Under suitable conditions, 6-phenylbenzo[b]indeno[1,2-e]-1,2-thiazine is also formed. These structures are confirmed by alternative syntheses. The molecular structure of 3a has been determined by single crystal X-ray diffraction. Compound 3a crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 20.777(3) Å, b = 6.130(3) Å, c = 31.327(3) Å, 3 = 99.59(1)°, and Z = 8. The structure was solved by direct methods and refined by least squares to a final R = 0.055. The molecular structure of 3a shows the three phenyl containing substituents to have the planes of their ring systems tilted between 40° and 60° from the plane of the indene system due to steric repulsions.

scholarly journals Synthesis, Crystal Structure, and DFT Calculations of 1,3-Diisobutyl Thiourea

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ataf A. Altaf ◽  
Adnan Shahzad ◽  
Zarif Gul ◽  
Sher A. Khan ◽  
Amin Badshah ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Single Crystal ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Model Support

1,3-Diisobutyl thiourea was synthesized and characterized by single crystal X-ray diffraction. It gives a monoclinic (α=γ= 90 andβ  ≠90) structure with the space group P21/c. The unit cell dimensions area= 11.5131 (4) Å,b= 9.2355 (3) Å,c= 11.3093 (5) Å,α= 90°,β= 99.569° (2),γ= 90°,V= 1185.78 (8) Å3, andZ= 4. The crystal packing is stabilized by intermolecular (N–H⋯S) hydrogen bonding in the molecules. The optimized geometry and Mullikan's charges of the said molecule calculated with the help of DFT using B3LYP-6-311G model support the crystal structure.

Cluster Chemistry. XLVII. X-Ray Crystal Structure of OsPt2(μ-CO)3(CO)2(PPh3)3

1986 ◽  
Vol 39 (12) ◽  
pp. 2145 ◽  
Author(s):  
MI Bruce ◽  
MR Snow ◽  
ERT Tiekink
Keyword(s):  
Crystal Structure ◽  
X Ray Diffraction ◽  
Cluster Chemistry ◽  
Triclinic Space Group ◽  
X Ray ◽  
Metal Atoms ◽  
Metal Metal ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Triphenylphosphine Ligand

The crystal structure of OsPt2(μ-CO)3(CO)2(PPh3)3 has been determined by single-crystal X-ray diffraction techniques. Crystals are triclinic, space group Pī with unit cell dimensions a 13.593(4), b 15.839(4), c 12.633(8) Ǻ, α 102.97(3), β 108.18(2), γ 84.86(3)° with Z2. The structure was refined by a full-matrix least-squares procedure on 5896 reflections [I ≥ 2.5σ(I)] to final R 0.028 and Rw 0.034. A triphenylphosphine ligand binds each of the metal atoms disposed at the corners of a triangle. Each metal-metal bond is spanned by a bridging carbonyl group. The coordination about the osmium atom is completed by two terminal carbonyl groups.

Synthesis and crystal structure of Na3.5Cr1.5Co0.5(PO4)3 phosphate

2006 ◽  
Vol 21 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Mohamed Chakir ◽  
Abdelaziz El Jazouli ◽  
Jean-Pierre Chaminade
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Hexagonal Unit Cell ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

A new Nasicon phosphates series [Na3+xCr2−xCox(PO4)3(0⩽x⩽1)] was synthesized by a coprecipitation method and structurally characterized by powder X-ray diffraction. The selected compound Na3.5Cr1.5Co0.5(PO4)3 (x=0.5) crystallizes in the R3c space group with the following hexagonal unit-cell dimensions: ah=8.7285(3) Å, ch=21.580(2) Å, V=1423.8(1) Å3, and Z=6. This three-dimensional framework is built of PO4 tetrahedra and Cr∕CoO6 octahedra sharing corners. Na atoms occupy totally M(1) sites and partially M(2) sites.

Crystal structure of a synthetic aluminoan tantalian titanite: a reconnaissance study

2006 ◽  
Vol 70 (1) ◽  
pp. 115-121 ◽  
Author(s):  
R. P. Liferovich ◽  
R. H. Mitchell
Keyword(s):  
Crystal Structure ◽  
Structural Data ◽  
Rietveld Analysis ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Ceramic Synthesis ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractA synthetic analogue, Ca(Ti0.6Al0.2Ta0.16Nb0.04)OSiO4, of an aluminoan tantalian titanite previously described from Craveggia pegmatite (Piemonte, Italy) has been prepared by a ceramic synthesis technique and its crystal structure determined by Rietveld analysis of the powder X-ray diffraction pattern. The synthetic Al-Ta-Nb-rich titanite adopts space group A2/a implying that substitutions at the single octahedral site destroy the coherence of the off-centering of octahedral chains in the titanite structure resulting in a P21/a → A2/a phase transition. Unit-cell dimensions obtained for the Al-Ta-Nb-rich titanite are: a = 7.0649(1) Å; b = 8.7187(1) Å; c = 6.5701(1) Å; β = 113.755(1)°, V = 370.41(1) Å3. The extensive replacement of Ti by Al, Ta and Nb results in a considerable decrease in the distortion of all coordination polyhedra in the structure of this titanite. These structural data suggest that a solid solution CaTi1-x(Alx/2 [Ta,Nb]x/2)OSiO4 (0 ≤ x ≤ 0.4) adopting the titanite structure might exist.

scholarly journals Synthese und Umsetzungen von 4-Acyl/Carbamoyl-N-aryl-3-chloropyrrol-2,5-dionen: Kristallstruktur eines auf Wasserstoffbrückenbindungen basierenden supramolekularen Bandes [1] / Synthesis and Reactions of 4-Acyl/Carbamoyl-N-aryl-3-chloro-pyrrol-2,5-diones: Crystal Structure of a Supramolecular Ribbon Based on Hydrogen Bonds [ 1]

1996 ◽  
Vol 51 (8) ◽  
pp. 1084-1098 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Bernd Hörner ◽  
Stephan Reck ◽  
Jochen Nachtrab ◽  
Eva-Maria Peters ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Diffraction Analysis ◽  
Thionyl Chloride ◽  
Oxalyl Chloride ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray

Reaction of malondiamides 1 with oxalyl chloride (2) leads to the formation of 2,3-dioxo-2,3- dihydrofuran hydrochlorides 3 and 2,3-dioxo-2,3-dihydro-furanes 4, respectively. The structure of 3a was established by X-ray diffraction. The β-oxo-dibenzylamides 5 react with 2 regiospecifically to give the 2,3-dioxo-2,3-dihydrofuranes 6. Addition of water in 1,4-position to 6a yields hydroxy-enol 7, which forms bimolecular aggregates via intermolecular hydrogen bonds as shown by X-ray analysis. Intramolecular C,N-bisacylation of β-oxoamides 8 and malondiamides 11 with 2 leads to the pyrrol-2,5-diones 9 and 12. Reaction of the enols 9 and 12 with thionyl chloride leads to 3-chloro-pyrrol-2,5-diones 13. 3-Amino-pyrrol-2,5-diones 15 are obtained from 13 and amines 14, while 1, ω-diamines 16 yield the bispyrrol systems 17. X-ray diffraction analysis of 17g reveals a supramolecular ribbon based on intermolecular hydrogen bonds between two different conformeres of 17g and in addition establishes unequivocally the imid-structures of 9 and 12. Intermolecular cyclisation of 13 with amino-tetrazol 18 gives the azido-pyrrolo-pyrimidine-diones 20, which reacts with triphenylphosphane to give phosphinimines 22. The structure of 22a was established by X-ray diffraction.

The crystal structure of C.I. Pigment Red 2, 1′-(2,5-dichlorophenyl)azo-2′hydroxy-3′-phenylamidonaphthalene

1977 ◽  
Vol 146 (4-6) ◽  
Author(s):  
A. Whitaker
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Intramolecular Hydrogen

AbstractThe crystal and molecular structure of C.I. Pigment Red 2, l′-(2,5-dichlorophenyl)azo-2′-hydroxy-3′-phenylamidonaphthalene has been determined by x-ray diffraction techniques. It crystallizes in the monoclinic system with cell parametersThe hydrogen atoms have been found and included but not refined. The final residual is 15.3%. The molecule is probably in the form of the hydrazone tautomer. The intramolecular hydrogen bonds keep most of the molecule approximately planar while it appears that the remainder is held in the same plane due to steric hinderence between the molecules. The molecules are packed in columns with alternate molecules antiparallel and are linked by van der Waals forces.

Crystal structure determination of new compounds Li6MB3O9 (M=Nd,Sm,Eu,Tm,Er)

2008 ◽  
Vol 23 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Y. F. Lou ◽  
W. Y. Wang ◽  
G. M. Cai ◽  
Y. P. Sun ◽  
C. Wang
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Crystal Structure Analysis ◽  
X Ray Diffraction ◽  
Space Group ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
New Compounds

New compounds Li6MB3O9 (M=Nd,Sm,Eu,Tm,Er) were synthesized by solid-state reaction. The crystal structure of Li6NdB3O9 was analyzed from both powder and single crystal X-ray diffraction data. The results obtained by powder diffraction analysis and Rietveld refinement are a=7.2725(4) Å, b=16.6398(9) Å, c=6.7529(5) Å, β=105.398(8)°, and space group P21/c, which agree with the results obtained by single crystal diffraction analysis: a=7.2712(4) Å, b=16.6268(9) Å, c=6.7484(4) Å, β=105.411(1)°, and space group P21/c. This compound is isostructural with Li6YB3O9. Single crystal structure analysis showed that the fundamental building unit of these isostructural compounds comprises three isolated [BO3]3− triangles, one distorted [NdO8]13− triangulated dodecahedron, four distorted [LiO5]9− five-coordinated polyhedra, and two [LiO4]7− tetrahedron. An analysis of the infrared spectrum of Li6NdB3O9 confirmed the presence of isolated [BO3]3− triangles in Li6NdB3O9. The remaining four Li6MB3O9 (M=Nd, Sm, Eu, Tm, and Er) compounds were found to be isostructural with Li6NdB3O9. Their unit cell dimensions decrease with an increase in the atomic number of the rare-earth atoms. DTA and TGA measurements of Li6MB3O9 (M=Nd, Sm, Eu, Tm, and Er) revealed that these borates congruently melt from 800 °C to 860 °C.

scholarly journals Pressure-induced polymorphism in cyclopropylamine

2005 ◽  
Vol 61 (6) ◽  
pp. 717-723 ◽  
Author(s):  
Patricia Lozano-Casal ◽  
David R. Allan ◽  
Simon Parsons
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Amino Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Graph Set ◽  
Unit Cell Dimensions

The crystal structure of cyclopropylamine at 1.2 GPa has been determined by X-ray diffraction methods. The structure of this phase is orthorhombic, space group Pbca and the unit-cell dimensions are a =  5.0741 (10), b  =  9.7594 (10) and c  =  13.305 (2) Å. Only one of the two H atoms of the amino group actively participates in the formation of the hydrogen-bonded chains, C(2) in graph-set notation, which lie parallel to the crystallographic a axis. Additionally, the topology of the crystal packing is studied using both Voronoi–Dirichlet polyhedra and Hirshfeld surface analyses for the low-temperature and the high-pressure structures of cyclopropylamine and the results are compared.

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