Search results for "Crystal"
showing 10 items of 22886 documents
6-Amino-2-iminiumyl-4-oxo-1,2,3,4-tetrahydropyrimidin-5-aminium sulfate monohydrate
2019
The title compound, C4H9N5O2+·SO4 2−·H2O, is the monohydrate of the commercially available compound `C4H7N5O·H2SO4·xH2O'. It is obtained by reprecipitation of C4H7N5O·H2SO4·xH2O from dilute sodium hydroxide solution with dilute sulfuric acid. The crystal structure of anhydrous 2,4,5-triamino-1,6-dihydropyrimidin-6-one sulfate is known, although called by the authors 5-amminium-6-amino-isocytosinium sulfate [Bieri et al. (1993). Private communication (refcode HACDEU). CCDC, Cambridge, England]. In the structure, the sulfate group is deprotonated, whereas one of the amino groups is protonated (R 2C—NH3 +) and one is rearranged to a protonated imine group (R 2C=NH2 +). This arrangement is very…
Crystal structure of dimethylammonium hydrogen oxalate hemi(oxalic acid)
2015
The title salt consists of a dimethylammonium cation (Me2NH2 +), an hydrogenoxalate anion (HC2O4 −), and half a molecule of oxalic acid (H2C2O4) situated about an inversion center. They are linked together through intermolecular hydrogen bonds, forming a two-dimensional bilayer-like self-assembly.
Acetylhydroxamic acid
2017
There is one independent molecule in the asymmetric unit of the title compound (alternatively namedN-hydroxyacetamide), C2H5NO2. It crystallizes in the noncentrosymmetric space groupP43. The structure is an anhydrous form of acetylhydroxamic acid with typical geometry that corresponds well with the hydrated structure described by Bracher & Small [Acta Cryst.(1970), B26, 1705–1709]. In the crystal, N—H...O and O—H...O hydrogen bonds connect the molecules into chains in thec-axis direction.
A tetranuclear cubane-like nickel(II) complex with a tridentate salicylideneimine Schiff base ligand: tetrakis[μ3-4-methyl-N-(2-oxidophenyl)salicylid…
2016
The tetranuclear title complex, [Ni4(C14H11NO2)4(CH3OH)4]·0.8CH3OH, has a distorted cubane topology shaped by four Schiff base ligands. The cubane [Ni4(μ3-O4)] core is formedviathe O atoms from the Schiff base ligands. The octahedrally coordinated NiIIions occupy alternating vertices of the cube. Each NiIIion is coordinated by oneO,N,O′-tridentate dianionic ligand, two O atoms of oxidophenyl groups from adjacent ligands and the O atom of a coordinating methanol molecule. The cubane core is stabilizedviaan intramolecular O—H...O hydrogen bond between the hydroxy group of the coordinating methanol molecules and the phenolate O atom of the aldehyde Schiff base fragment. Additional stabilizatio…
Crystal structure of N,N,N′,N′,N′′,N′′-hexamethylguanidinium cyanate 1.5-hydrate
2015
The title hydrated salt, C7H18N3+·OCN−.1.5H2O, was synthesized starting fromN,N,N′,N′,N′′,N′′-hexamethylguanidinium chloride by a twofold anion-exchange reaction. The asymmetric unit contains two cations, two cyanate anions and three water molecules. One cation shows orientational disorder and two sets of N-atom positions were found related by a 60° rotation, with an occupancy ratio of 0.852 (6):0.148 (6). The C—N bond lengths in both guanidinium ions range from 1.329 (2) to 1.358 (10) Å, indicating double-bond character, pointing towards charge delocalization within the NCN planes. Strong O—H...N hydrogen bonds between the crystal water molecules and the cyanate ions and strong O—H...O hyd…
Crystal structure and Hirshfeld surface analysis of a pyridiniminium bromide salt: 1-[2-(adamantan-1-yl)-2-oxoethyl]pyridin-4-iminium bromide
2018
The asymmetric unit of the title pyridiniminium halide salt comprise of one cation and one anion. In the crystal, molecules are linked by N—H⋯Br and C—H⋯O hydrogen bonds, C—H⋯π interactions, and π–π interactions into layers. The intermolecular interactions in the crystal structure are quantified by Hirshfeld surface analysis.
{Bis[2-(diisopropylphosphanyl)ethyl]amine}carbonyl(tetrahydroborato)cobalt(I)
2018
In the structure of title borohydride pincer complex, [Co(BH4)(C16H37NP2)(CO)], the cobalt(I) metal exhibits a distorted square-pyramidal coordination geometry with the basal positions occupied by the P and N atoms of the tridentate ligand and by the C atom of the carbon monoxide ligand. In the crystal, molecules interact only by van der Waals forces.
A Gadolinium(III) Complex Based on the Thymine Nucleobase with Properties Suitable for Magnetic Resonance Imaging
2021
The paramagnetic gadolinium(III) ion is used as contrast agent in magnetic resonance (MR) imaging to improve the lesion detection and characterization. It generates a signal by changing the relaxivity of protons from associated water molecules and creates a clearer physical distinction between the molecule and the surrounding tissues. New gadolinium-based contrast agents displaying larger relaxivity values and specifically targeted might provide higher resolution and better functional images. We have synthesized the gadolinium(III) complex of formula [Gd(thy)2(H2O)6](ClO4)3·2H2O (1) [thy = 5-methyl-1H-pyrimidine-2,4-dione or thymine], which is the first reported compound based on gadolinium…
Crystal structure of chlorido(2-{1-[2-(4-chlorophenyl)hydrazin-1-ylidene-κN]ethyl}pyridine-κN)(η5-pentamethylcyclopentadienyl)rhodium(III) chloride
2015
The title compound, [Rh(η5-C5Me5)Cl(C13H12ClN3)]Cl, is chiral at the metal and crystallizes as a racemate. Upon coordination, the hydrazinylidenepyridine ligand is non-planar, an angle of 54.42 (7)° being observed between the pyridine ring and the aromatic ring of the [2-(4-chlorophenyl)hydrazin-1-ylidene]ethyl group.
3-Bromopyridine-2-carbonitrile
2019
The title compound, C6H3BrN2, also known as 3-bromopicolinonitrile, was synthesized by cyanation of 2,3-dibromopyridine. In the solid state, short intermolecular Br...N contacts are observed. Additionally, the crystal packing is consolidated by π–π stacking interactions with centroid–centroid distances of 3.7893 (9) Å.