oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Search Results: 1 - 10 of 3038 matches for " Sean Parkin "
All listed articles are free for downloading (OA Articles)
Page 1 /3038
Display every page Item
Tetraethylammonium (2,2′-bipyridine)tetracyanidocobaltate(III) sesquihydrate acetonitrile solvate
Ganna Lyubartseva,Sean Parkin
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810011311
Abstract: The title complex, (C8H20N)[Co(CN)4(C10H8N2)]·CH3CN·1.5H2O, consists of tetraethyl ammonium cations, mononuclear [CoIIIbpy(CN)4] anions and uncoordinated water and acetonitrile molecules. The CoIII atom is six-coordinated by two 2,2′-bipyridine (bpy) N atoms and four cyanide C atoms in a distorted octahedral geometry. The acute bite angle of the chelating bpy [82.28 (8)°] is the main factor accounting for this distortion. In addition, the tetraethylammonium cation is significantly disordered [occupancy ratio 0.611 (3):0.389 (3)]. The presence of water molecules, one of which is disordered over two positions about an inversion center, results in the formation of a network of O—H...N hydrogen bonds involving the cyanide N atoms.
Dichloridobis(3,4,5-trimethyl-1H-pyrazole-κN2)cobalt(II)
Ganna Lyubartseva,Sean Parkin
Acta Crystallographica Section E , 2010, DOI: 10.1107/s160053681003254x
Abstract: In the title compound, [CoIICl2(C6H10N2)2], a pair of 3,4,5-trimethylpyrazoles act as monodentate ligands. Two Cl anions are also bonded directly to the CoII atom, which has a CoN2Cl2 chromophore in a slightly distorted tetrahedral geometry. The two molecules in the asymmetric unit are related by an approximate twofold rotation roughly parallel to the a axis. The amino H atom in the pyrazole ring participates in weak N—H...Cl hydrogen bonds to form chains that propagate roughly parallel to the c axis.
Bis(tripyrazol-1-ylmethane)nickel(II) tetracyanidonickelate(II) dihydrate
Ganna Lyubartseva,Sean Parkin
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809046108
Abstract: The title complex, [Ni(C10H10N6)2][Ni(CN)4]·2H2O, contains an octahedral nickel(II) cation and a square-planar nickel(II) anion. Both the cation and the anion reside on a crystallographic center of inversion. The NiII center in the cation is coordinated by six pyrazol-1-yl rings of two chelating tripyrazol-1-ylmethane [HC(pz)3] ligands, with Ni—N distances that range between 2.0647 (19) and 2.0828 (19) . The NiII center in the anion is coordinated by four cyanide ligands, with Ni—C distances in the range 1.869 (2)–1.869 (3) . The [Ni(CN)4]2 anions are linked by inversion-related water molecules into extended chains that run parallel to the a axis.
(11R)-13-Dimethylammonio-11,13-dihydro-4,5-epoxycostunolide semifumarate
Sundar Neelakantan,Sean Parkin,Peter A. Crooks
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809021941
Abstract: Crystals of the title salt, C17H28NO3+·C4H3O4 , were obtained by reacting parthenolide with dimethylamine followed by conversion of the amine adduct into a water-soluble fumarate salt. Subsequent crystallization of the fumarate salt from water afforded colorless orthorhombic crystals. The amine addition is highly stereospecific yielding exclusively a single diastereomer with R-configuration at the newly formed C-11 chiral carbon. In the crystal, intermolecular O—H...O and N—H...O hydrogen bonds help to establish the packing.
Bis[tris(3,5-dimethyl-1H-pyrazol-1-yl-κN2)methyl]sodium trifluoromethanesulfonate
Ganna Lyubartseva,Sean Parkin,Uma Prasad Mallik
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812028413
Abstract: In the title salt, [Na(C16H22N6)2]CF3SO3, the Na+ cation is coordinated by six N atoms from two tridentate tris(3,5-dimethylpyrazol-1-yl)methane ligands in a distorted octahedral geometry. The Na—N distances range from 2.427 (3) to 2.507 (3) , intra-ligand N—Na—N angles range from 74.71 (8) to 79.31 (9)°, and adjacent inter-ligand N—Na—N angles range between 100.42 (9) and 104.97 (9)°. The structure is twinned by inversion [occupancy factors = 0.50 (9)] and the trifluoromethanesulfonate anion is disordered, with two end-over-end orientations of unequal occupancy [0.781 (3) and 0.219 (3)].
Bis[tris(1H-pyrazol-1-yl-κN2)methane]nickel(II) bis{[tris(1H-pyrazol-1-yl-κN2)methane]tris(thiocyanato-κN)nickelate(II)} methanol disolvate
Ganna Lyubartseva,Sean Parkin,Uma Prasad Mallik
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811045144
Abstract: Attempts to prepare the mononuclear [(tpm)NiIIL3] 1 [tpm = tris(1H-pyrazol-1-yl)methane and L = thiocyanate] anion yielded the methanol-solvated salt, [(tpm)2NiII][(tpm)NiII(NCS)3]2·2CH3OH or [Ni(C10H10N6)2][Ni(NCS)3(C10H10N6)]2·2CH3OH. The asymmetric unit consists of half a centrosymmetric bis[tris(1H-pyrazol-1-yl)methane]nickel(II) cation and an octahedral nickelate(II) anion bound to one tpm and three L ligands, and a methanol solvent molecule. One of the L ligands is disordered over two positions with occupancy factors of 0.650 (3) and 0.350 (3). There are O—H...S interactions between the methanol and the disordered thiocyanate anion, and a weak C—H...O hydrogen bond between the cation and the methanol O atom.
(11R)-13-[2-(4-Hydroxyphenyl)ethylamino]-4,5-epoxy-11,13-dihydrocostunolide monohydrate
Shama. Nasim,Sean Parkin,Peter A. Crooks
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808003863
Abstract: The title compound (systematic name: 12-{[2-(4-hydroxyphenyl)ethyl]aminomethyl}-4,8-dimethyl-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one monohydrate), C23H31NO4·H2O, was obtained by the reaction of tyramine with parthenolide. The configuration of the new chiral center in the title compound is R, establishing the stereospecificity of the amination reaction. The water molecule is disordered over three positions; the site occupancy factors are 0.45, 0.40 and 0.15.
(11R,13R)-13-(Tetralin-1-ylamino)-4,5-epoxy-11,13-dihydrocostunolide
Shama Nasim,Sean Parkin,Peter A. Crooks
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808003322
Abstract: The title compound [systematic name: (12R)-4,8-dimethyl-12-[(1′R)-1′,2′,3′,4′-tetrahydro-1′-naphthyl)aminomethyl]-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one}, C25H33NO3, was formed from the reaction of (1R)-1-aminotetralin with parthenolide in methanolic solution. X-ray crystal structure analysis determined that the configuration of the new chiral center in the title compound was R.
5-Fluoro-1-(pentanoyl)pyrimidine-2,4(1H,3H)-dione
Hans-Joachim Lehmler,Sean Parkin
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808004418
Abstract: The pentanoyl group and the 5-fluorouracil moiety of the title compound, C9H11FN2O3, are essentially coplanar, with the pentanoyl carbonyl group oriented towards the ring CH group and away from the nearer ring carbonyl group. In the crystal structure, two inversion-related molecules form a dimer structure, in which two N—H...O hydrogen bonds generate an intermolecular R22(8) ring. In addition, there are intra- and intermolecular C—H...O interactions.
5-Fluoro-1-(3-metylbutanoyl)pyrimidine-2,4(1H,3H)-dione
Hans-Joachim Lehmler,Sean Parkin
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808006296
Abstract: The 3-methylbutanoyl group and the 5-fluorouracil unit of the title compound, C9H11FN2O3, are essentially coplanar, with the carbonyl group oriented towards the ring CH group and away from the nearer ring carbonyl group. The 3-methylbutanoyl (C=)C—N—C=O torsion angle of 9.6 (2)° is comparable to that in structurally related compounds. In the solid state, two inversion-related molecules form N—H...O hydrogen bonds to generate an intermolecular R22(8) ring. The crystal structure also diplays intra- and intermolecular C—H...O interactions.
Page 1 /3038
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.