Strained heterocyclic systems. 12. The crystal structure of 1,8-diazabiphenylene

1984 ◽  
Vol 62 (11) ◽  
pp. 2235-2237 ◽  
Author(s):  
Betty R. Deroski ◽  
John S. Ricci Jr ◽  
J. A. Hugh MacBride ◽  
J. Hodge Markgraf
Keyword(s):  
Crystal Structure ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Aromatic Rings ◽  
Space Group ◽  
X Ray ◽  
Planar Molecule ◽  
Ray Methods

The structure of 1,8-diazabiphenylene (5) has been determined by X-ray methods. Crystals of 5 are monoclinic, space group P21/n, with a = 3.786(2), b = 8.532(1), c = 11.218 (2) Å, β = 92.24(2)°, and two molecules per unit cell. The planar molecule contains distorted aromatic rings with the smallest angle (112.9°) adjacent to the fused strained ring.

Über die Kristallstruktur von KSc2 F7 / The Crystal Structure of KSc2 F7

1985 ◽  
Vol 40 (6) ◽  
pp. 726-729 ◽  
Author(s):  
Klaus Güde ◽  
Christoph Hebecker
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Unit Cell ◽  
Space Group ◽  
X Ray ◽  
Monoclinic Unit Cell ◽  
R Value ◽  
Ray Methods

Abstract Single crystals of KSc2F7 have been prepared from a mixture of KF and ScF3 . The samples were investigated by X-ray methods. KSc2F7 crystallizes orthorhombically with a = 10.643(2), b = 6.540(1), c = 4.030(1) Å. These data indicate a close crystallographic connection to the monoclinic unit cell of KIn2F7 [1], But in contrast to KIn2F7 , KSc2 F7 crystallizes in space group No. 65. Cmmm - D192h. The R-value for 341 observed independent reflections is 0.060.

Anionische Komplexe [Mo2(O2CPh)4X2]2⊖ mit X = N3, Cl, Br. Die Kristallstruktur von (PPh4)2[Mo2(O2CPh)4Cl2] · 2CH2Cl2 / Anionic Complexes [Mo2(O2C-Ph)4X2]2⊖ with X = N3, Cl, Br. The Crystal Structure of (PPh4)2[Mo2(O2C-Ph)4Cl2] · 2CH2Cl2

1985 ◽  
Vol 40 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Kay Jansen ◽  
Kurt Dehnicke ◽  
Dieter Fenske
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Diffraction Data ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Anionic Complexes

The syntheses and IR spectra of the complexes [Mo2(O2C-Ph)4X2]2⊖ with X = N3, CI, Br and the counter ion PPh4⊕ are reported. The azido and the bromo complexes are obtained from a solution of [Mo2(O2CPh)4] with PPh4N3 in pyridine or by reaction with PPh4Br in CH2Br2, respectively. When (PPh4)2[Mo2(O2CPh)4(N3)2] is dissolved in CH2Cl2, nitrogen is evolved and the complex with X = CI is obtained. The crystal structure of (PPh4)2[Mo2(O2CPh)4Cl2] · 2CH2Cl2 was determined from X-ray diffraction data (5676 observed independent reflexions, R = 0.042). It crystallizes in the monoclinic space group P21/n with four formula units per unit cell; the lattice constants are a = 1549, b = 1400, c = 1648 pm, β = 94.6°. The centrosymmetric [Mo2(O2CPh)4Cl2]2⊖ ion has a rather short Mo-Mo bond of 213 pm, whereas the MoCl bonds are very long (288 pm)

Notizen: Eine neue bicyclische Zinn-Selen-Verbindung. Synthese und Kristallstruktur von [{Cp(CO)2Fe}3ClSn3Se4] / A New Bicyclic Tin Selenium Compound. Synthesis and Crystal Structure of [{Cp(CO)2Fe}3ClSn3Se4]

1993 ◽  
Vol 48 (7) ◽  
pp. 1009-1012 ◽  
Author(s):  
Kurt Merzweiler ◽  
Harald Kraus
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Synthesis And Crystal Structure ◽  
Selenium Compound ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Compound Synthesis

[{Cp(CO)2Fe}SnCl3] reacts with Na2Se in THF to form the compound [{Cp(CO)2Fe}3ClSn3Se4] 1. 1 crystallizes in the monoclinic space group P21/n with 4 formula units per unit cell. The lattice constants are α = 1435.2(7), b = 1124.4(4), c = 1972.7(12) pm, β = 94.59(4)°. According to the X-ray structure determination 1 contains a bicyclic Sn3Se4 framework.

NTO Polymorphs

1992 ◽  
Vol 296 ◽  
Author(s):  
Kien-yin Lee ◽  
Richard Giloxdi
Keyword(s):  
Crystal Structure ◽  
Cell Density ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Triclinic Space Group ◽  
Space Group ◽  
Monoclinic Form ◽  
Network Of Hydrogen Bonds ◽  
Air Bag ◽  
Ray Methods

AbstractNTO is an explosive of current interest. It has been evaluated as an insensitive component to replace RDX in the bomb fill, and as a major ingredient for the auto air bag system. The crystal structure of the β from of NTO has been determined by single-crystal X-ray methods. The unit cell is monoclinic, space group P21/c, with a = 9.326, b = 5.515, c = 9.107 Å, β = 100.77°. There are four molecules in the cell, density 1.878 g/cm3. Infinite extension of H-bonding in two-dimensional sheets occurs in the monoclinic form. Bond lengths and angles all have normal values.Efforts have been made to determine the crystal structure of α-NTO. However, a structure refined only to R = 17% was obtained, probably due to some kind of twinning about the crystal needle axis. The unit cell is triclinic, space group P1, with a = 5.12, b = 10.30, c = 17.9 Å, α = 106.7°, β= 97.7°, γ = 90.2°. There are eight molecules in the cell, density 1.92 g/cm3. Ribbons of NTO molecules formed by a relatively strong network of hydrogen bonds are observed. It was found that α-NTO is the stable, dominating form. A variety of techniques have been chosen to identify the two polymorphs.

Die Kristallstruktur von Di-μ-hydroxo-bis[aquotriamminkobalt(III)]-nitrat-2-Hydrat / The Crystal Structure of Di-μ-hydroxo-bis[aquotriamminecobalt (III)] - nitrate-2-hydrate

1971 ◽  
Vol 26 (10) ◽  
pp. 987-989 ◽  
Author(s):  
Karl Wieghardt
Keyword(s):  
Crystal Structure ◽  
Complex Cation ◽  
Monoclinic Space Group ◽  
Spatial Behaviour ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Ray Methods

The crystal structure of Di-µ-hydroxy-bis [aquo-triamminecobalt (III)] nitrate-2-hydrate has been determined by x-ray diffraction using counter techniques. The compound crystallizes in the monoclinic space group C2h5-P21/n with a=9.444 (2), b=9.684 (3), c=10.736 (3) Å, β=90.1 (2)°, Z= 2. A total of 1765 independent reflections was used in solving the structure, which was refined to a conventional R1-factor of 0.047. It was not possible to distinguish by x-ray methods between the oxygen and nitrogen atoms of the NH3- and H2O molecules in the complex cation, because of their similarity in point of electrostatical and spatial behaviour.

Molecular and crystal structure of a copper(II) complex of sildenafil

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Piperazine Ring ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

scholarly journals Die Kristallstruktur von Calciumhexacyanoferrat(II)- Hexamethylentetramin-Wasser(1/1/6) Ca2 [Fe(CN)6] · C6H12N4 · 6H2O / The Crystal Structure of Calciumhexacyanoferrate(II)- Hexamethylenetetramine-Water(1/1/6) Ca2[Fe(CN)6] · C 6H12N4 · 6H2O

1988 ◽  
Vol 43 (2) ◽  
pp. 135-137 ◽  
Author(s):  
H.-Jürgen Meyer ◽  
Joachim Pickardt
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Determination ◽  
Unit Cell ◽  
Single Crystal Structure ◽  
Crystal Structure Determination ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray

Ca2[Fe(CN)6] · C6H12N4 · 6H2O crystallizes in the monoclinic space group B2/b with a = 1130,2(4), b = 1373,5(4), c = 1353,0(4) pm and γ = 97,17°. The X-ray single crystal structure determination converged at R = 0.055 (2057 reflections). Each of the four Fe(CN)6 octahedra (Z = 4) in the unit cell is coordinated by six Ca atoms with mean NCYAN - Ca distances of 253.5(3) pm. The Ca atoms are bridged by hexamethylenetetramine and water molecules

Oxotetrafluoro-vanadate(V): Die Kristallstruktur von [enH2] [VOF4(H2O)]2.

1976 ◽  
Vol 31 (5) ◽  
pp. 541-543 ◽  
Author(s):  
Helmut Rieskamp ◽  
Rainer Mattes
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Trans Position ◽  
Space Group ◽  
X Ray ◽  
In Trans ◽  
Oxygen Atoms

The crystal structure of [enH2][VOF4(H2O)]2 has been determined from X-ray diffractometer data. Crystals are monoclinic, space group C2/c with Z = 4 in a unit cell of dimensions a = 16.576(13), b = 7.781(4), c = 10.338(8) Å, β = 120.0(1)°.The structure was refined by least-squares methods to R 0.053 for 1436 reflections. The structure contains monomeric [VOF4(H2O)]⁻-ions with the oxygen atoms in trans position. The bond distances are 1.577 Å (terminal oxygen) and 2.333 Å (H2O molecule), resp. The V–F distances vary between 1.769(2) and 1.858(2) Å for fluorine atoms involved in strong hydrogen bonds.

The Crystal Structure of Bis(2,2′:6′,2″-terpyridine)nickel(II) Perchlorate Hydrate

1995 ◽  
Vol 48 (7) ◽  
pp. 1373 ◽  
Author(s):  
AT Baker ◽  
DC Craig ◽  
AD Rae
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystal ◽  
Least Squares ◽  
Axial Compression ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Octahedral Symmetry ◽  
Space Group ◽  
X Ray

The crystal structure of bis (2,2′:6′,2″-terpyridine)nickel(II) bis (perchlorate) hydrate has been determined by single-crystal X-ray diffractometry . The compound is monoclinic, space group P21, with two molecules in a unit cell of dimensions a 8.827(4), b 8.910(2), c 20.148(9) Ǻ, β 98.71(2)°. The structure was refined by least-squares to a residual of 0.065 for 2184 observed reflections. The compound is found to be isomorphic with the iron(II) analogue previously reported: the cation has approximate D2d symmetry, with the main distortion from octahedral symmetry being an axial compression. Both the solid state reflectance and solution spectra have been measured and some significant differences are noted.

Crystal structure and reference X-ray pattern of Ba4Ti10Al2O27

1998 ◽  
Vol 13 (3) ◽  
pp. 178-184 ◽  
Author(s):  
J. A. Kaduk ◽  
B. H. Toby ◽  
W. Wong-Ng ◽  
W. Greenwood
Keyword(s):  
Crystal Structure ◽  
Diffraction Pattern ◽  
Rietveld Refinement ◽  
Complex Network ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray

The crystal structure of Ba4Ti10Al2O27 has been refined in a joint Rietveld refinement using neutron and X-ray powder data. The compound crystallizes in the monoclinic space group C2/m, with a=19.7057(3), b=11.3575(2), c=9.8318(2) Å, β=109.218(1)°, and V=2077.81(5) Å3. It is isostructural to Ba4Ti10Fe2O27 and Ba4Ti11ZnO27, and consists of a complex network of corner- and edge-sharing Ti/Al octahedra. The structure can best be described based on close-packed O/Ba-O layers in an 8-layer (8L) chhcchhc sequence. Out of a total of ten Ti/Al sites, Al was found to substitute for Ti mainly in four sites, and the remaining six sites were predominantly occupied by Ti. The unit cell contents derived from the refined site occupancies are Ba16Ti40.48Al7.52O108, essentially identical to the expected Ba16Ti40Al8O108. A reference diffraction pattern of this phase is also reported.

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