scholarly journals Crystal structure of methyl α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyranoside monohydrate

Author(s):  
Lars Eriksson ◽  
Göran Widmalm

The title compound, C13H24O9·H2O, a structural model for part of bacterial O-antigen polysaccharides from Shigella flexneri and Escherichia coli, crystallizes with four independent disaccharide molecules and four water molecules in the asymmetric unit. The conformation at the glycosidic linkage joining the two rhamnosyl residues is described by the torsion angles φH of 39, 30, 37 and 37°, and ψH of −32, −35, −31 and −32°, which are the major conformation region known to be populated in an aqueous solution. The hexopyranose rings have the 1 C 4 chair conformation. In the crystal, the disaccharide and water molecules are associated through O—H...O hydrogen bonds, forming a layer parallel to the bc plane. The layers stack along the a axis via hydrophobic interactions between the methyl groups.

2014 ◽  
Vol 70 (10) ◽  
pp. o1088-o1089
Author(s):  
Fiorella Meneghetti ◽  
Daniela Masciocchi ◽  
Arianna Gelain ◽  
Stefania Villa

The asymmetric unit of the title compound, C15H16N2O3, contains two independent molecules, which present a different conformation of the carboxylic acid side chain [C—C—C—OH torsion angles = 65.3 (7) and −170.1 (5)°]. In both molecules, the dihydropyridazinone ring adopts a geometry intermediate between a twisted-boat and a half-chair conformation, while the central six-membered ring is almost in a half-boat conformation. In the crystal, molecules are linked by O—H...Ok(k = ketone) hydrogen bonds, generating [01-1] chains. Aromatic π–π stacking contacts between the benzene and the dihydropyridazinone rings [centroid–centroid distance [3.879 (9) Å] are also observed.


2014 ◽  
Vol 70 (4) ◽  
pp. o419-o420
Author(s):  
Yan-Jiao Gao ◽  
Jie Ma ◽  
Xiao Zheng

The title compound, C32H35NO4, is an unexpected product obtained in the SmI2-mediated radical cross-coupling of a lactam 2-pyridyl sulfone with an arone. The asymmetric unit contains two molecules. In both molecules, the core pyrrolidinone ring adopts an approximate envelope conformation (with the C atom bearling the benzyloxy substituent as the flap) and the cyclohexyl ring has a chair conformation. The relative orientation of the two substitutent groups at the 4- and 5-positions of the pyrrolidinone ring isantiin both molecules, with O(benzyloxy)—C—C—C(benzene) torsion angles of 150.8 (3) and 154.2 (2)°. In the crystal, C—H...O interactions involving carbonyl groups as acceptors lead to the formation of a tape motif propagating parallel to thea-axis direction.


Author(s):  
Kai-Hang Liu ◽  
Jian-Ming Gu ◽  
Xiu-Rong Hu ◽  
Gu-Ping Tang

There are two canagliflozin molecules (AandB) and one water molecule in the asymmetric unit of the title compound, C24H25FO5S·0.5H2O [systematic name: (2S,3R,4R,5S,6R)-2-(3-{[5-(4-fluorophenyl)thiophen-2-yl]methyl}-4-methylphenyl)-6-(hydroxymethyl)-3,4,5,6-tetrahydro-2H-pyran-3,4,5-triol hemihydrate]. The dihedral angles between the methylbenzene and thiophene rings are 115.7 (4) and 111.7 (4)°, while the dihedral angles between the fluorobenzene and thiophene rings are 24.2 (6) and 20.5 (9)° in moleculesAandB, respectively. The hydropyran ring exhibits a chair conformation in both canagliflozin molecules. In the crystal, the canagliflozin molecules and lattice water molecules are connectedviaO—H...O hydrogen bonds into a three-dimensional supramolecular architecture.


2012 ◽  
Vol 68 (4) ◽  
pp. m464-m465 ◽  
Author(s):  
Teik Beng Goh ◽  
Mohd Nizam Mordi ◽  
Sharif Mahsufi Mansor ◽  
Mohd Mustaqim Rosli ◽  
Hoong-Kun Fun

The asymmetric unit of the title compound, (C13H17N2O)2[ZnCl4]·2H2O, contains two tetrahydroharmine cations, one tetrachlorozincate(II) anion and two water molecules. In the cations, the two 1H-indole ring systems are essentially planar, with maximum deviations of 0.016 (2) and 0.018 (2) Å, and both tetrahydropyridinium rings show a half-chair conformation. The ZnIIcomplex anion has a distorted tetrahedral geometry. In the crystal, intermolecular N—H...O, N—H...Cl, O—H...O, O—H...Cl and C—H...O hydrogen bonds link the components into a three-dimensional network. A π–π interaction with a centroid–centroid distance of 3.542 (14) Å is also observed.


2007 ◽  
Vol 63 (3) ◽  
pp. m905-m907 ◽  
Author(s):  
Hazel S. Wilkinson ◽  
William T. A. Harrison

In the title compound, C4H12N2 2+·HAsO4 2−·H2O, the component species interact by way of N—H...O and O—H...O hydrogen bonds, the latter leading to infinite sheets of HAsO4 2− anions and water molecules containing R 6 6(18) loops. The asymmetric unit contains one anion, one water molecule and half each of two centrosymmetric cations.


2014 ◽  
Vol 70 (2) ◽  
pp. m75-m75 ◽  
Author(s):  
Marwa Mghandef ◽  
Habib Boughzala

The asymmetric unit of the title inorganic–organic hybrid compound, (C10H16N2O)[CoCl4]·H2O, consists of a tetrahedral [CoCl4]2−anion, together with a [C10H18N2O]2+cation and a water molecule. Crystal cohesion is achieved through N—H...Cl, O—H...Cl and N—H...O hydrogen bonds between organic cations, inorganic anions and the water molecules, building up a three-dimensional network.


2013 ◽  
Vol 69 (11) ◽  
pp. o1698-o1698 ◽  
Author(s):  
Svitlana V. Shishkina ◽  
Igor V. Ukrainets ◽  
Lidiya A. Petrushova

There are two independent molecules in the asymmetric unit of the title compound, C13H13NO5S, in both of which the ester substituent is nearly coplanar [C—C—C—O torsion angles = 2.7 (7) and −0.8 (7)°] with the planar fragment of the bicycle due to the formation of a strong O—H...O intramolecular hydrogen bond. The vinyl group at the ring N atom is approximately orthogonal to the heterocyclic mean plane [C—N—C—C torsion angles = 103.1 (6) and 98.2 (5)°]. The refinement was performed on a two-component, non-merohedrally twinned crystal [population ratio = 0.483 (3):0.517 (3).


Author(s):  
Ramazan Tatsız ◽  
Veli T. Kasumov ◽  
Tuncay Tunc ◽  
Tuncer Hökelek

The asymmetric unit of the title compound, C22H25F2N4O2, contains two crystallographically independent molecules. In one molecule, the two benzene rings are oriented at a dihedral angle of 1.93 (10)° and in the other molecule the corresponding dihedral angle is 7.19 (9)°. The piperidine rings in the two molecules adopt a similar distorted chair conformation, and both have pseudo-mirror planes passing through the N—O bonds. An intramolecular O—H...N hydrogen bond between the hydroxy group and the imine N atom is observed in both molecules. In the crystal, weak C—H...O and C—H...F hydrogen bonds, enclosingR22(6) ring motifs, and weak π–π stacking interactions link the molecules into a three-dimensional supramolecular network, with centroid-to-centroid distances between the nearly parallel phenyl and benzene rings of adjacent molecules of 3.975 (2) and 3.782 (2) Å.


IUCrData ◽  
2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Kathleen S. Lee ◽  
Luke Turner ◽  
Cynthia B. Powell ◽  
Eric W. Reinheimer

The title compound, C16H14FNO3, was synthesized via solid phase methods; it exhibits monoclinic (P21) symmetry at room temperature. The two independent molecules that comprise the asymmetric unit display distinct torsion angles of 173.2 (2) and 72.6 (2)° along the central sp 3 C—N bond. In the crystal, hydrogen bonding through N—H...O contacts couples the asymmetric unit molecules into pairs that align in layers extending parallel to (100) via additional O—H...O interactions. The phenyl ring of one independent molecule was found to be disordered over two sets of sites in a 0.55 (3):0.45 (3) ratio.


IUCrData ◽  
2018 ◽  
Vol 3 (8) ◽  
Author(s):  
Błażej Dziuk ◽  
Anna Jezuita

The asymmetric unit of the title compound, C10H9N2 +·0.5C2O4 2−·C2H2O4·H2O, consists of a 2,2′-bipyridinium cation, half an oxalate dianion, one oxalic acid and one water molecule. One N atom in 2,2′-bipyridine is unprotonated, while the second is protonated and forms an N—H...O hydrogen bond. In the crystal, the anions are connected with surrounding acid molecules and water molecules by strong near-linear O—H...O hydrogen bonds. The water molecules are located between the anions and oxalic acids; their O atoms participate as donors and acceptors, respectively, in O—H...O hydrogen bonds, which form sheets arranged parallel to the ac plane.


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