Search results for "Papers"
showing 10 items of 345 documents
Tribenzylammonium chloride
2014
Single crystals of the title salt, C21H21NH+·Cl−, were isolated as a side product from the reaction involving [(C6H5CH2)3NH]2[HPO4] and Sn(CH3)3Cl in ethanol. Both the cation and the anion are situated on a threefold rotation axis. The central N atom in the cation has a slightly distorted tetrahedral environment, with angles ranging from 107.7 to 111.16 (10)°. In the crystal, the tribenzylammonium cations and chloride anions are linked through N—H...Cl and C—H...Cl hydrogen bonds, leading to the formation of infinite chains along [001]. The crystal studied was a merohedral twin.
Properties and interactions – melting point of tribromobenzene isomers
2021
The melting points of tribromobenzene isomers are correlated with the number, nature and distribution of intermolecular interactions in their structures.
2-(Mesitylmethylsulfanyl)pyridineN-oxide–18-crown-6 (2/1)
2008
In the title compound, 2C(15)H(17)NOS·C(12)H(24)O(6), the asymmetric unit consists of one N-oxide derivative and one-half of the 18-crown-6 ether, which lies on an inversion centre. In the crown ether, the O-C-C-O torsion angles indicate a gauche conformation of the ethyl-eneoxy units, while the C-O-C-C torsion angles indicate planarity of these segments. In the N-oxide unit, the dihedral angle between the pyridine and benzene rings is 85.88 (12)°. The crystal packing is stabilized by weak C-H⋯O hydrogen bonds and C-H⋯π inter-actions.
(S,S,S,S)-Nebivolol hydro-chloride hemihydrate.
2012
The asymmetric unit of the title hydrated salt, C22H26F2NO4+·Cl−·0.5H2O, consists of an (S,S,S,S)-nebivolol {nebivol = bis[2-(6-fluoro-3,4-dihydro-2H-1-benzopyran-2-yl)-2-hydroxyethyl]ammonium} cation, a chloride anion and a half-occupancy water molecule. The dihedral angle between the mean planes of the benzene rings is 50.34 (12)°. The pyran rings adopt half-chair conformations. The crystal packing features O—H...O hydrogen bonds and weak N—H...Cl, O—H...Cl, and O—H...Cl interactions, producing layers along (010).
5-Amino-1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid
2009
In the title compound, C11H8F3N3O2, there are two molecules in the asymmetric unit wherein the phenyl rings make dihedral angles of 65.3 (2) and 85.6 (2)° with the pyrazole rings. In the crystal, pairs of molecules are held together by O—H...O hydrogen bonds between the carboxyl groups, forming a centrosymmetric dimer with an R22(8) motif. Intramolecular N—H...O interactions are also present.
N-[(1S,2S)-2-Amino-1,2-diphenylethyl]-4-methylbenzenesulfonamide [(S,S)-TsDPEN]
2010
The crystal structure of the title compound, C21H22N2O2S, shows a network of N—H...N and N—H...O hydrogen bonds. The tolyl and 1-phenyl rings are almost mutually coplanar [7.89 (9)°], while the 2-phenyl ring makes a dihedral angle of 50.8 (1) ° with the 1-phenyl ring. An intramolecular N—H...N hydrogen bond stabilizes the molecular conformation.
4-[4-(4-Fluoro-phen-yl)-2-methyl-5-oxo-2,5-dihydro-isoxazol-3-yl]-1-methyl-pyridinium iodide-4-[3-(4-fluoro-phen-yl)-2-methyl-5-oxo-2,5-dihydro-isoxa…
2007
The crystal structure of the title compound, C(16)H(16)FN(2)O(2) (+)·I(-), was determined as part of a study of the biological activity of isoxazolone derivatives as p38 mitogen-activated protein kinase (MAPK) inhibitors. The X-ray crystal structure of 4-[4-(4-fluoro-phenyl)-2-methyl-5-oxo-2,5-dihydro-isoxazol-3-yl]-1-methyl-pyridinium iodide showed the presence of the regioisomer 4-[3-(4-fluoro-phenyl)-2-methyl-5-oxo-2,5-dihydro-isoxazol-4-yl]-1-methyl-pyridinium iodide. The synthesis of the former compound was achieved by reacting 4-(4-fluoro-phenyl)-3-(4-pyridyl)isoxazol-5(2H)-one after treatment with Et(3)N in dimethyl-formamide, with iodo-methane. The unexpected formation of the regioi…
Allylammonium hydrogen oxalate hemihydrate
2014
In the title hydrated molecular salt, C3H8N+·C2HO4−·0.5H2O, the water O atom lies on a crystallographic twofold axis. The C=C—C—N torsion angle in the cation is 2.8 (3)° and the dihedral angle between the CO2and CO2H planes in the anion is 1.0 (4)°. In the crystal, the hydrogen oxalate ions are linked by O—H...O hydrogen bonds, generating [010] chains. The allylammonium cations bond to the chains through N—H...O and N—H...(O,O) hydrogen bonds. The water molecule accepts two N—H...O hydrogen bonds and makes two O—H...O hydrogen bonds. Together, the hydrogen bonds generate (100) sheets.
B-DNA Structure and Stability as Function of Nucleic Acid Composition. Dispersion-Corrected DFT Study of Dinucleoside-Monophosphate Single and Double…
2013
actions of the sugar-phosphate skeleton with water; (6) hydrophobic interactions of the DNA cylindrical core, made up by the hydrogen-bonded and stacked nitrogen bases, with the water solvent. Recently, there has been increasing effort in developing and applying quantum chemical methods able to reproduce the structure of native B-DNA and to correctly describe the energy involved in the intrastrand and interstrand noncovalent interactions between the nucleotide monomers. This topic has been approached by both wave function methods and density functional theory. [2] Water solvent and sodium counterions also play an important role in the formation and relative stabilization of the double-helic…
2-(3,5-Dimethyl-1H-pyrazol-1-yl)-2-hy-droxy-imino-N'-[1-(pyridin-2-yl)ethyl-idene]acetohydrazide.
2012
In the title compound, C14H16N6O2, the dihedral angles formed by the mean plane of the acetohydrazide group [maximum deviation 0.0629 (12) A] with the pyrazole and pyridine rings are 81.62 (6) and 38.38 (4)° respectively. In the crystal, molecules are connected by N—H⋯O and O—H⋯N hydrogen bonds into supramolecular chains extending parallel to the c-axis direction.