Crystal structure of tricyclo-DNA: an unusual compensatory change of two adjacent backbone torsion angles

2008 ◽  
pp. 883-885 ◽  
Author(s):  
Pradeep S. Pallan ◽  
Damian Ittig ◽  
Annie Héroux ◽  
Zdzislaw Wawrzak ◽  
Christian J. Leumann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Torsion Angles ◽  
Compensatory Change

Crystal Forms of Semisynthetic Ergot Alkaloid Terguride

2002 ◽  
Vol 67 (4) ◽  
pp. 479-489 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Ivana Císařová ◽  
Ladislav Cvak ◽  
Alexandr Jegorov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ergot Alkaloid ◽  
Simplified Model ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
X Ray Diffraction ◽  
Torsion Angles ◽  
Crystal Forms ◽  
X Ray ◽  
Independent Molecules

Two new structures of semisynthetic ergot alkaloid terguride created by unusual number of symmetry-independent molecules were determined by X-ray diffraction methods at 150 K. Form A (monoclinic, P212121, Z = 12) contains three symmetry-independent terguride molecules and two molecules of water in the asymmetric part of the unit cell. The form CA (monoclinic, P21, Z = 8) is an anhydrate remarkable by the presence of four symmetry-independent molecules in the crystal structure. Conformations of twelve symmetry-independent molecules that were found in four already described terguride structures are compared with torsion angles obtained by ab initio quantum-mechanical calculations for the simplified model of N-cyclohexyl-N'-diethylurea.

Darstellung und Kristallstruktur des Bis(diisobutylammonium)-heptasulfids [H2N(i-C4H9)2]2S7 / Synthesis and Crystal Structure of Bis(diisobutylammonium)-heptasulfide [H2N(i-C4H9)2]2S7

1993 ◽  
Vol 48 (12) ◽  
pp. 1732-1736 ◽  
Author(s):  
C. Müller ◽  
P. Böttcher
Keyword(s):  
Crystal Structure ◽  
Orthorhombic Space Group ◽  
Trans Conformation ◽  
Torsion Angles ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Lattice Constants ◽  
Ethanol Yields ◽  
The Common

The reaction of diisobutylamine, H2S, and sulfur in a mixture of dimethylformamide, formamide, and ethanol yields orange crystals of bis(diisobutylammonium)-heptasulfide. The compound crystallizes in the centrosymmetric orthorhombic space group Pbca, the lattice constants are a = 11.234(4), b = 17.875(7), c = 27.009(10) Å. The S72-chain does not have the common helical all-trans-conformation, but a mixed conformation trans-cis-trans (sequence of the signs of torsion angles + + - - and - - + +).

scholarly journals Crystal structure ofN-(1-allyl-3-chloro-4-ethoxy-1H-indazol-5-yl)-4-methoxybenzenesulfonamide

2014 ◽  
Vol 70 (9) ◽  
pp. o1029-o1030
Author(s):  
Hakima Chicha ◽  
El Mostapha Rakib ◽  
Latifa Bouissane ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Three Dimensional ◽  
Ring System ◽  
Torsion Angles ◽  
Compound C ◽  
Dimensional Network

In the title compound, C19H20ClN3O4S, the benzene ring is inclined to the indazole ring system (r.m.s. deviation = 0.014 Å) by 65.07 (8)°. The allyl and ethoxy groups are almost normal to the indazole ring, as indicated by the respective torsion angles [N—N—C—C = 111.6 (2) and C—C—O—C = −88.1 (2)°]. In the crystal, molecules are connected by N—H...N hydrogen bonds, forming helical chains propagating along [010]. The chains are linked by C—H...O hydrogen bonds, forming a three-dimensional network.

Darstellung und Kristallstruktur des Bis(trimethylammonium)hexasulflds [HN(CH3)3]2S6 / Preparation and Crystal Structure of Bis(trimethylammonium)hexasulfide [HN(CH3)3]2S6

1994 ◽  
Vol 49 (4) ◽  
pp. 489-493 ◽  
Author(s):  
C. Müller ◽  
P. Böttcher
Keyword(s):  
Crystal Structure ◽  
Monoclinic Space Group ◽  
Trans Conformation ◽  
Torsion Angles ◽  
Space Group ◽  
Lattice Constants ◽  
Ethanol Yields

The reaction of trimethylamine, H2S, and sulfur in ethanol yields orange crystals of bis(trimethylammonium) hexasulfide. The com pound crystallizes in the centrosymmetric monoclinic space group P 2/c. The lattice constants are a = 10.310(7), b = 5.752(2), c = 13.348(10) Å, β = 98.41(6)°. The S26-chain has a helical all-trans-conformation (sequence of the signs of torsion angles +++ and --- ).

scholarly journals Crystal structure of sodium (1S)-D-lyxit-1-ylsulfonate

2016 ◽  
Vol 72 (5) ◽  
pp. 628-631
Author(s):  
Alan H. Haines ◽  
David L. Hughes
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Chain Structure ◽  
Zigzag Chain ◽  
Sugar Chain ◽  
Open Chain ◽  
Torsion Angles ◽  
Hydroxymethyl Group ◽  
Sodium Hydrogen ◽  
Group Form

The title compound, Na+·C5H11O8S−[systematic name: sodium (1S,2S,3S,4R)-1,2,3,4,5-pentahydroxypentane-1-sulfonate], is formed by reaction of D-lyxose with sodium bisulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure in which one of the oxygen atoms of the sulfonate residue, the S atom, the C atoms of the sugar chain and the O atom of the hydroxymethyl group form an essentially planar zigzag chain with the corresponding torsion angles lying between 179.80 (11) and 167.74 (14)°. A three-dimensional bonding network exists in the crystal structure involving hexacoordination of sodium ions by O atoms, three of which are provided by a single D-lyxose–sulfonate unit and the other three by two sulfonate groups and one hydroxymethyl group, each from separate units of the adduct. Extensive intermolecular O—H...O hydrogen bonding supplements this bonding network.

Struktur und X-X-Elektronendichteverteilung in Diaminoboranen des Typs (RCH3N)2BCH3 mit R = H, CH3

1991 ◽  
Vol 46 (1) ◽  
pp. 84-96 ◽  
Author(s):  
Norbert Niederprüm ◽  
Roland Boese ◽  
Günter Schmid
Keyword(s):  
Crystal Structure ◽  
Electron Density ◽  
Zone Melting ◽  
Infrared Light ◽  
Monoclinic Space Group ◽  
Difference Electron Density ◽  
Orthorhombic Space Group ◽  
Torsion Angles ◽  
Space Group ◽  
The Mean

Using a miniature zone melting device with focused infrared light it was possible to grow crystals of bis(dimethylamino)methylborane (1) and bis(monomethylamino)methylborane (2) at temperatures o f 182 K and 177 K, respectively. The crystal structure and the X - X difference electron density have been determined at temperatures o f 120 K (1) and 115 K (2).1 crystallizes in the orthorhombic space group Pbca with a = 758.87(7), b = 1559.74(12) and c = 1296.73(12) pm. The mean B - N distance is 143.1(3) pm.2 crystallizes in the monoclinic space group P21/c with a = 775.06(6), b = 1533.94(17), c = 1011.06(10) pm and β = 102.669(7)° with intermolecular N ··· H hydrogen bridges. The mean B - N distance is 141.5(2) pm.It is shown that the variation of torsion angles at small angles has more influence on bond lengths than the same or a greater variation at large angles and that it is necessary to pay more attention to the torsion angles ( C - B - N - C ) rather than to the interplanar angles (plane N ,B,N - plane N ,C,C ).

Conformational analysis of the disaccharide methyl α-D-mannopyranosyl-(1→3)-2-O-acetyl-β-D-mannopyranoside monohydrate

2019 ◽  
Vol 75 (6) ◽  
pp. 610-615 ◽  
Author(s):  
Wenhui Zhang ◽  
Qingquan Wu ◽  
Allen G. Oliver ◽  
Anthony S. Serianni
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Structural Parameters ◽  
Side Chain ◽  
Glycosidic Linkage ◽  
Torsion Angles ◽  
Conformational Properties ◽  
Statistical Program ◽  
Acetyl Group

The crystal structure of methyl α-D-mannopyranosyl-(1→3)-2-O-acetyl-β-D-mannopyranoside monohydrate, C15H26O12·H2O, (II), has been determined and the structural parameters for its constituent α-D-mannopyranosyl residue compared with those for methyl α-D-mannopyranoside. Mono-O-acetylation appears to promote the crystallization of (II), inferred from the difficulty in crystallizing methyl α-D-mannopyranosyl-(1→3)-β-D-mannopyranoside despite repeated attempts. The conformational properties of the O-acetyl side chain in (II) are similar to those observed in recent studies of peracetylated mannose-containing oligosaccharides, having a preferred geometry in which the C2—H2 bond eclipses the C=O bond of the acetyl group. The C2—O2 bond in (II) elongates by ∼0.02 Å upon O-acetylation. The phi (φ) and psi (ψ) torsion angles that dictate the conformation of the internal O-glycosidic linkage in (II) are similar to those determined recently in aqueous solution by NMR spectroscopy for unacetylated (II) using the statistical program MA′AT, with a greater disparity found for ψ (Δ = ∼16°) than for φ (Δ = ∼6°).

scholarly journals 2-({[(Pyridin-1-ium-2-ylmethyl)carbamoyl]formamido}methyl)pyridin-1-ium bis(3,5-dicarboxybenzoate): crystal structure and Hirshfeld surface analysis

2016 ◽  
Vol 72 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Mukesh M. Jotani ◽  
Sabrina Syed ◽  
Siti Nadiah Abdul Halim ◽  
Edward R. T. Tiekink
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Torsion Angle ◽  
Three Dimensional ◽  
Hirshfeld Surface ◽  
Carbonyl Groups ◽  
Amide Hydrogen ◽  
Asymmetric Unit ◽  
Torsion Angles ◽  
First Approximation

The asymmetric unit of the title salt, C14H16N4O22+·2C9H5O6−, comprises half a dication, being located about a centre of inversion, and one anion, in a general position. The central C4N2O2group of atoms in the dication are almost planar (r.m.s. deviation = 0.009 Å), and the carbonyl groups lie in anantidisposition to enable the formation of intramolecular amide-N—H...O(carbonyl) hydrogen bonds. To a first approximation, the pyridinium and amide N atoms lie to the same side of the molecule [Npy—C—C—Namidetorsion angle = 34.8 (2)°], and theantipyridinium rings are approximately perpendicular to the central part of the molecule [dihedral angle = 68.21 (8)°]. In the anion, one carboxylate group is almost coplanar with the ring to which it is connected [Cben—Cben—Cq—O torsion angle = 2.0 (3)°], whereas the other carboxylate and carboxylic acid groups are twisted out of the plane [torsion angles = 16.4 (3) and 15.3 (3)°, respectively]. In the crystal, anions assemble into layers parallel to (10-4)viahydroxy-O—H...O(carbonyl) and charge-assisted hydroxy-O—H...O(carboxylate) hydrogen bonds. The dications are linked into supramolecular tapes by amide-N—H...O(amide) hydrogen bonds, and thread through the voids in the anionic layers, being connected by charge-assisted pyridinium-N—O(carboxylate) hydrogen bonds, so that a three-dimensional architecture ensues. An analysis of the Hirshfeld surface points to the importance of O—H...O hydrogen bonding in the crystal structure.

scholarly journals Crystal structure of (S)-5-chloro-N-({2-oxo-3-[4-(3-oxomorpholin-4-yl)phenyl]oxazolidin-5-yl}methyl)thiophene-2-carboxamide

2018 ◽  
Vol 74 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Jie Shen ◽  
Gu-Ping Tang ◽  
Xiu-Rong Hu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Supramolecular Architecture ◽  
Asymmetric Unit ◽  
Torsion Angles ◽  
Independent Molecules

The asymmetric unit of the crystal of the title compound (common name rivaroxaban), C19H18ClN3O5, contains two rivaroxaban molecules with different conformations; the C—C—N—C torsion angles between the oxazolidine and thiophene rings are −171.1 (7) and −106.8 (9)° in the two independent molecules. In the crystal, classical N—H...O hydrogen bonds and weak C—H...O hydrogen bonds link the molecules into a three-dimensional supramolecular architecture.

scholarly journals Crystal structure of 6-chloro-5-isopropylpyrimidine-2,4(1H,3H)-dione

2014 ◽  
Vol 70 (11) ◽  
pp. o1144-o1145
Author(s):  
Nadia G. Haress ◽  
Hazem A. Ghabbour ◽  
Ali A. El-Emam ◽  
C. S. Chidan Kumar ◽  
Hoong-Kun Fun
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Pyrimidine Ring ◽  
Isopropyl Group ◽  
Torsion Angles ◽  
Compound C ◽  
Dimensional Network

In the molecule of the title compound, C7H9ClN2O2, the conformation is determined by intramolecular C—H...O and C—H...Cl hydrogen bonds, which generateS(6) andS(5) ring motifs. The isopropyl group is almost perpendicular to the pyrimidine ring with torsion angles of −70.8 (3) and 56.0 (3)°. In the crystal, two inversion-related molecules are linkedviaa pair of N—H...O hydrogen bonds intoR22(8) dimers; these dimers are connected into chains extending along thebcplaneviaan additional N—H...O hydrogen bond and weaker C—H...O hydrogen bonds. The crystal structure is further stabilized by a weak π–π interaction [3.6465 (10) Å] between adjacent pyrimidine-dione rings arranged in a head-to-tail fashion, producing a three-dimensional network.

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