The effect of partial methylation of the glycine amino group on crystal structure inN,N-dimethylglycine and its hemihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o283-o287 ◽  
Author(s):  
Vasily S. Minkov ◽  
Elena V. Boldyreva
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecules ◽  
Amino Group ◽  
Asymmetric Unit ◽  
Partial Methylation ◽  
Space Groups ◽  
Carboxylate Groups ◽  
Anhydrous Compound ◽  
Additional Hydrogen

N,N-Dimethylglycine, C4H9NO2, and its hemihydrate, C4H9NO2·0.5H2O, are discussed in order to follow the effect of the methylation of the glycine amino group (and thus its ability to form several hydrogen bonds) on crystal structure, in particular on the possibility of the formation of hydrogen-bonded `head-to-tail' chains, which are typical for the crystal structures of amino acids and essential for considering amino acid crystals as mimics of peptide chains. Both compounds crystallize in centrosymmetric space groups (PbcaandC2/c, respectively) and have twoN,N-dimethylglycine zwitterions in the asymmetric unit. In the anhydrous compound, there are no head-to-tail chains but the zwitterions formR44(20) ring motifs, which are not bonded to each other by any hydrogen bonds. In contrast, in the crystal structure ofN,N-dimethylglycinium hemihydrate, the zwitterions are linked to each other by N—H...O hydrogen bonds into infiniteC22(10) head-to-tail chains, while the water molecules outside the chains provide additional hydrogen bonds to the carboxylate groups.

scholarly journals Crystal structure of poly[diaquabis(μ5-benzene-1,3-dicarboxylato)(N,N-dimethylformamide)cadmium(II)disodium(I)]

2017 ◽  
Vol 73 (11) ◽  
pp. 1599-1602 ◽  
Author(s):  
Matimon Sangsawang ◽  
Kittipong Chainok ◽  
Nanthawat Wannarit
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Carboxylate Groups ◽  
Benzene Rings ◽  
Coordinated Water ◽  
Coordinate Geometry

The title compound, [CdNa2(C8H4O4)2(C3H7NO)(H2O)2]nor [CdNa2(1,3-bdc)2(DMF)(H2O)2]n, is a new CdII–NaIheterobimetallic coordination polymer. The asymmetric unit consists of one CdIIatom, two NaIatoms, two 1,3-bdc ligands, two coordinated water molecules and one coordinated DMF molecule. The CdIIatom exhibits a seven-coordinate geometry, while the NaIatoms can be considered to be pentacoordinate. The metal ions and their symmetry-related equivalents are connectedviachelating–bridging carboxylate groups of the 1,3-bdc ligands to generate a three-dimensional framework. In the crystal, there are classical O—H...O hydrogen bonds involving the coordinated water molecules and the 1,3-bdc carboxylate groups and π–π stacking between the benzene rings of the 1,3-bdc ligands present within the frameworks.

scholarly journals Crystal structure ofrac-(3aR,4S,5aR,6S,9R,10aS,10bR)-3a,5a,9-trimethyltetradecahydro-6,9-epoxycyclohepta[e]inden-4-ol monohydrate

2015 ◽  
Vol 71 (9) ◽  
pp. o690-o691 ◽  
Author(s):  
Andreas Schäfer ◽  
Christopher Golz ◽  
Hans Preut ◽  
Carsten Strohmann ◽  
Martin Hiersemann
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Organic Molecules ◽  
Membered Ring ◽  
Methyl Groups ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Relative Configuration ◽  
Space Groups ◽  
A Chain

The title hydrate, C17H28O2·H2O, was synthesized in order to determine the relative configuration of the tetracyclic framework. The fused 5,6,7-tricarbocyclic core exhibits an entirecis-annulation, featuring a 1,4-cis-relation of the angular methyl groups in the six-membered ring. The oxa bridge of the epoxycycloheptane moiety is oriented towards the concave face of the boat-shaped molecule, whereas the angular methyl groups are directed towards the convex face. The asymmetric unit of the crystal contains two nearly identical formula units, which are relatedviaa pseudo-centre of symmetry. The structure could be solved in the space groupsI-4 andI41/a. The refinement in the acentric space group, however, gave significantly better results and these are used in this paper. O—H...O hydrogen bonds are observed between the organic molecules, between the organic molecules and the water molecules, and between the water molecules, forming a chain along thec-axis direction.

Tetrakis(tert-butylammonium) benzene-1,2,4,5-tetracarboxylate octahydrate

2007 ◽  
Vol 63 (11) ◽  
pp. o4315-o4315
Author(s):  
Krzysztof Ejsmont ◽  
Jacek Zaleski
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Carboxylate Groups

In the crystal structure of the title compound, 4C4H12N+·C10H2O8 4−·8H2O, there is a centre of symmetry at the centre of the benzene ring; the asymmetric unit comprises one half-anion, two cations and four water molecules. The pyromellitate tetraanion is nonplanar; it and the cations exhibit normal geometry. The two unique carboxylate groups are twisted out of the plane of the benzene ring by about 40 and 50°. The network formed by the ions and water molecules is based on eight O—H...O and six N—H...O strong hydrogen bonds.

scholarly journals Crystal structure and Hirshfeld surface analysis of 2,4-diamino-6-phenyl-1,3,5-triazin-1-ium 4-methylbenzenesulfonate

2018 ◽  
Vol 74 (8) ◽  
pp. 1159-1162
Author(s):  
Ramalingam Sangeetha ◽  
Kasthuri Balasubramani ◽  
Kaliyaperumal Thanigaimani ◽  
Savaridasson Jose Kavitha
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Hirshfeld Surface ◽  
Amino Group ◽  
Asymmetric Unit ◽  
Graph Set ◽  
Molecular Salt ◽  
Sulfonate Anion ◽  
Hydrogen Bonded

In the title molecular salt, C9H10N5 +·C7H7O3S−, the asymmetric unit consists of a 2,4-diamino-6-phenyl-1,3,5-triazin-1-ium cation and a 4-methylbenzenesulfonate anion. The cation is protonated at the N atom lying between the amine and phenyl substituents. The protonated N and amino-group N atoms are involved in hydrogen bonding with the sulfonate O atoms through a pair of intermolecular N—H...O hydrogen bonds, giving rise to a hydrogen-bonded cyclic motif with R 2 2(8) graph-set notation. The inversion-related molecules are further linked by four N—H...O intermolecular interactions to produce a complementary DDAA (D = donor, A = acceptor) hydrogen-bonded array, forming R 2 2(8), R 4 2(8) and R 2 2(8) ring motifs. The centrosymmetrically paired cations form R 2 2(8) ring motifs through base-pairing via N—H...N hydrogen bonds. In addition, another R 3 3(10) motif is formed between centrosymetrically paired cations and a sulfonate anion via N—H...O hydrogen bonds. The crystal structure also features weak S=O...π and π–π interactions. Hirshfeld surface and fingerprint plots were employed in order to further study the intermolecular interactions.

scholarly journals Rerefinement of poly[diaquabis(μ3-2-methylpropanoato-κ4 O:O,O′:O′)bis(μ3-2-methylpropanoato-κ3 O:O:O)(μ2-2-methylpropanoato-κ3 O:O,O′)(2-methylpropanoato-κ2 O,O′)trilead(II)]

IUCrData ◽  
2020 ◽  
Vol 5 (10) ◽  
Author(s):  
Erika Samolová ◽  
Jan Fábry
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Layered Structure ◽  
Title Complex ◽  
Water Molecules ◽  
X Ray ◽  
Positional Disorder ◽  
Coordination Numbers ◽  
Carboxylate Groups ◽  
Accuracy And Precision

The crystal structure of the title complex, [Pb3(C4H7O2)6(H2O)2] n , was redetermined on basis of modern CCD-based single-crystal X-ray data at 120 K. The current study basically confirms the previous report [Fallon et al. (1997). Polyhedron, 16, 19–23] at 190 K, but with higher accuracy and precision. In particular, positional disorder of one of the 2-methylpropanoate anions over two sets of sites was resolved, showing a refined ratio of the disorder components of 0.535 (9):0.465 (9). The three independent cations in the structure have coordination numbers of [7 + 1], [6 + 1], and [5 + 3], with O atoms belonging either to carboxylate groups or water molecules. This arrangement leads to the formation of sheets parallel to (\overline{1}01), whereby the hydrophobic 2-methylpropanyl groups of the anions are oriented above and below the hydrophilic sheets to form a layered structure. Within a sheet, hydrogen bonds of the type Owater—H...O are formed, whereas the hydrophobic groups between adjacent layers interact through van der Waals forces.

Quinidine sesquihydrate

2007 ◽  
Vol 63 (3) ◽  
pp. o1483-o1484
Author(s):  
Min-Jie Guo ◽  
Shu-Juan Zhang ◽  
Dong-Lan Sun ◽  
Zhi Fan
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Compound C

In the asymmetric unit of the title compound, C20H24N2O2·1.5H2O, there are two independent quinidine [systematic name: (1S,3R,4S,8R,9S)-4-[hydroxy(5-vinyl-1-azabicyclo[2.2.2]oct-2-yl)methyl]-6-methoxyquinoline] molecules and three water molecules. Intermolecular O—H...O and O—H...N hydrogen bonds stabilize the crystal structure.

scholarly journals Crystal structure of pentakis(ethylenediamine-κ2N,N′)lanthanum(III) trichloride–ethylenediamine–dichloromethane (1/1/1)

2014 ◽  
Vol 70 (11) ◽  
pp. 424-426 ◽  
Author(s):  
Hope T. Sartain ◽  
Richard J. Staples ◽  
Shannon M. Biros
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Electron Density ◽  
Inversion Center ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Bypass Procedure ◽  
Hydrogen Bonding Network ◽  
Additional Hydrogen

We report here the crystal structure of a ten-coordinate lanthanum(III) metal coordinated by five bidentate ethylenediamine ligands, [La(C2H8N2)5]Cl3·C2H8N2·CH2Cl2. One free ethylenediamine molecule and three Cl−anions are also located in the asymmetric unit. The overall structure is held together by an extensive hydrogen-bonding network between the Cl−anions and the NH groups on the metal-bound ethylenediamine ligands. The free ethylenediamine molecule is held in an ordered position by additional hydrogen bonds involving both the chlorides and –NH groups on the metal-bound ligands. One highly disordered molecule of dichloromethane is located on an inversion center; however, all attempts to model this disorder were unsuccessful. The electron density in this space was removed using the BYPASS procedure [van der Sluis & Spek (1990).Acta Cryst.A46, 194–201].

scholarly journals Bis(tetraethylammonium) oxalate dihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o2382-o2383 ◽  
Author(s):  
Timothy J. McNeese ◽  
Robert D. Pike
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Molar Ratio ◽  
Water Molecules ◽  
Oxalate Dihydrate ◽  
Carboxylate Groups ◽  
Graph Set ◽  
Oxalate Ion

The title compound, 2C8H20N+·C2O42−·2H2O, synthesized by neutralizing H2C2O4·2H2O with (C2H5)4NOH in a 1:2 molar ratio, is a deliquescent solid. The oxalate ion is nonplanar, with a dihedral angle between carboxylate groups of 64.37 (2)°. O—H...O hydrogen bonds of moderate strength link the O atoms of the water molecules and the oxalate ions into rings parallel to thecaxis. The rings exhibit the graph-set motifR44(12). In addition, there are weak C—H...O interactions in the crystal structure.

scholarly journals Crystal structure of 5,5-bis(4-methylbenzyl)pyrimidine-2,4,6(1H,3H,5H)-trione monohydrate

2015 ◽  
Vol 71 (1) ◽  
pp. 19-21 ◽  
Author(s):  
Bhaskarachar Ravi Kiran ◽  
Parameshwar Adimule Suchetan ◽  
Hosamani Amar ◽  
Giriyapura R Vijayakumar
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
Compound C ◽  
Independent Molecules

The asymmetric unit of the title compound, C20H20N2O3·H2O, contains two independent molecules (AandB), with similar conformations and two independent water molecules. In the crystal, N—H...O and Owater—H...O hydrogen bonds link all moieties into two crystallographically independent kinds of sheets parallel to theacplane. These independent sheets, each containing eitherAorBmolecules, are further alternately stacked along thebaxis and interconnectedviaC—H...πarylinteractions.

scholarly journals Crystal structure of 2,6-bis(2-hydroxy-5-methylphenyl)-4-phenylpyridinium bromide dichloromethane hemisolvate hemihydrate

2015 ◽  
Vol 71 (12) ◽  
pp. o953-o954
Author(s):  
Badma N. Mankaev ◽  
Kirill V. Zaitsev ◽  
Sergey S. Karlov ◽  
Mikhail P. Egorov ◽  
Andrei V. Churakov
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Pyridine Ring ◽  
Dihedral Angles ◽  
Water Molecules ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Compound C ◽  
Ring Centroid

The asymmetric unit in the structure of the title compound, C25H22NO2+·Br−·0.5CH2Cl2·0.5H2O, comprises two pseudosymmetry-related cations, two bromide anions, a dichloromethane molecule and a water molecule of solvation. The two independent cations are conformationally similar with the comparative dihedral angles between the central pyridine ring and the three benzene substituent rings being 3.0 (2), 36.4 (1) and 24.2 (1)°, and 3.7 (2), 36.5 (1) and 24.8 (1)°, respectively. In the crystal, the cations, anions and water molecules are linked through O—H...O and O—H...Br hydrogen bonds, forming an insular unit. Within the cations there are also intramolecular N—H...O hydrogen bonds. Adjacent centrosymmetrically related aggregates are linked by π–π stacking interactions between the pyridine ring and a benzene ring in both cations [ring-centroid separations = 3.525 (3) and 3.668 (3) Å], forming chains extending across theacdiagonal. Voids between these chains are filled by dichloromethane molecules.

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