333 research outputs found
Crystal structure of bromido-nitro-syl-bis(tri-phenyl-phosphane-κP)nickel(II).
The asymmetric unit of the title complex, [NiBr(NO){P(C6H5)3}2], comprises two independent mol-ecules each with a similar configuration. The Ni(II) cation is coordinated by one bromide anion, one nitrosyl anion and two tri-phenyl-phosphane mol-ecules in a distorted BrNP2 tetra-hedral coordination geometry. The coordination of the nitrosyl group is non-linear, the Ni-N-O angles being 150.2 (5) and 151.2 (5)° in the two independent mol-ecules. In the crystal, mol-ecules are linked by weak C-H⋯Br hydrogen bonds and weak C-H⋯π inter-actions into a three-dimensional supra-molecular architecture
4-{3-[Hydroxy(phenyl)methyl]-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-4-yl}benzenesulfonamide
In the title compound, C15H14N4O3S2, the hydroxy group is disordered over two positions with occupancies of 0.619 (5) and 0.381 (5). The benzene ring attached to the heterocycle makes a dihedral angle of 86.92 (9)° with respect to the best plane through the five-membered ring. The crystal packing is stabilized by intermolecular O—H⋯O, N—H⋯S, N—H⋯N, C—H⋯O and C—H⋯N hydrogen bonds, and N—H⋯π and C—H⋯π interactions
Aqua(dicyanamido-κN 1)(nitrato-κ2 O,O′)(2,3,5,6-tetra-2-pyridylpyrazine-κ3 N 2,N 1,N 6)manganese(II)
In the title compound, [Mn(C2N3)(NO3)(C24H16N6)(H2O)], the central manganese(II) ion is heptacoordinated to a tridentate 2,3,5,6-tetra-2-pyridylpyrazine ligand (tppz), a bidentate nitrate ligand, a terminal monodentate dicyanamide ligand (dca) and a water molecule. The structure contains isolated neutral complexes, which are linked by O(water)—H⋯N hydrogen bonds generating chains along [010]
Bis(2,3,5,6-tetra-2-pyridylpyrazine-κ3 N 2,N 1,N 6)iron(II) bis(dicyanamidate) 4.5-hydrate
In the title compound, [Fe(C24H16N6)2][N(CN)2]2·4.5H2O, the central iron(II) ion is hexacoordinated by six N atoms of two tridentate 2,3,5,6-tetra-2-pyridylpyrazine (tppz) ligands. Two dicyanamide anions [dca or N(CN)2
−] act as counter-ions, and 4.5 water molecules act as solvation agents. The structure contains isolated cationic iron(II)–tppz complexes and the final neutrality is obtained with the two dicyanamide anions. One of the dicyanamide anions and a water molecule are disordered with an occupancy ratio of 0.614 (8):0.386 (8). O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds involving dca, water and tppz molecules are observed
Bis(2,3,5,6-tetra-2-pyridylpyrazine-κ3 N 2,N 1,N 6)nickel(II) dithiocyanate dihydrate
In the title compound, [Ni(C24H16N6)2](NCS)2·2H2O, the central NiII ion is octahedrally coordinated by six N atoms of two tridentate 2,3,5,6-tetra-2-pyridylpyrazine ligands (tppz). Two thiocyanate anions act as counter-ions and two water molecules act as solvation agents. O—H⋯N hydrogen bonds are observed in the crystral structure
Trans-Dichloridobis(triphenylphosphine) palladium(II)
The title compound, [PdCl2{P(C6H5)3}2], has a slightly distorted square-planar geometry, with the chloride ligands coordinated in a trans configuration. The Pd atom is located on a centre of inversion
Expanding and Collapsing Scalar Field Thin Shell
This paper deals with the dynamics of scalar field thin shell in the
Reissner-Nordstrm geometry. The Israel junction conditions between
Reissner-Nordstrm spacetimes are derived, which lead to the equation
of motion of scalar field shell and Klien-Gordon equation. These equations are
solved numerically by taking scalar field model with the quadratic scalar
potential. It is found that solution represents the expanding and collapsing
scalar field shell. For the better understanding of this problem, we
investigate the case of massless scalar field (by taking the scalar field
potential zero). Also, we evaluate the scalar field potential when is an
explicit function of . We conclude that both massless as well as massive
scalar field shell can expand to infinity at constant rate or collapse to zero
size forming a curvature singularity or bounce under suitable conditions.Comment: 15 pages, 11 figure
4-Formylphenyl 2,3,4,6-tetra-O-acetyl-β-d-glucopyranoside
The pyranoside ring in the title compound, C21H24O11, has a chair conformation with the substituted benzene ring occupying an equatorial position. The crystal packing is dominated by C—H⋯O interactions that lead to the formation of supramolecular layers in the ab plane
2-(Benzenesulfonamido)acetic acid
The title compound, C8H9NO4S, is of interest as a precursor to biologically active sulfur-containing heterocyclic cmpounds. The crystal structure displays the classical O—H⋯O intermolecular hydrogen bonding typical for carboxylic acids forming dimers. Symmetry-related dimers are, in turn, linked through head-to-tail pairs of intermolecular N—H⋯O interactions, giving rise to a zigzag chain along the c axis
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