Search results for "Benzene"
showing 10 items of 1701 documents
Analyses of known and new types of polyhalogenated aromatic substances in oven ash from recycled aluminium production
2003
Abstract Persistent aromatic bromine, chlorine and mixed chlorine-bromine compounds were analysed from recycled aluminium smelter (ALS) ashes to explore the impact of brominated flame retardants (BFR) on their formation. Polybrominated diphenyl ethers (PBDE) were the most abundant original BFRs found. Induction furnace ash contained tetra- to octa-BDEs about 2000 ng g −1 in similar congener ratios as the original scrap, but contents of nona- and deca-BDEs were only 25 and 5 ng g −1 indicating their significant degradation in ALS process. In the most non-polar fraction, PCB levels and profiles were similar as earlier ALS ash samples in 1990s. The highest PCB level measured was that of deca-C…
Isobaric Vapor−Liquid Equilibrium of Binary Mixtures of 1-Butanol + Chlorobenzene and 2-Butanol + Chlorobenzene at 20 and 100 kPa
1997
Isobaric vapor−liquid equilibria were obtained for 1-butanol + chlorobenzene and for 2-butanol + chlorobenzene systems at 20 and 100 kPa using a dynamic still. The experimental error in temperature was ±0.1 K, in pressure ±0.01 kPa and ±0.1 kPa for the experiments carried out at 20 and 100 kPa, respectively, and in liquid and vapor composition ±0.001. The two systems satisfy the point-to-point thermodynamic consistency test. Both systems show a positive deviation from ideality. The data were correlated with the Wilson equation.
1-(2,3,5,6-Tetramethylbenzyloxy)-1H-benzotriazole
2009
In the title compound, C17H19N3O, the benzotriazole ring is essentially planar, with a maximum deviation of 0.0069 (15) Å. The mean plane of the benzotriazole ring forms a dihedral angle of 13.16 (4)° with the mean plane of the benzene ring. The crystal packing is stabilized by π–π stacking interactions, with a centroid–centroid distance of 3.8077 (12) Å, together with weak C—H...π interactions. Molecules are stacked along the a axis.
Reversible Dimerization of Tetraureas Derived from Calix[4]Arenes
1999
Calix[4]arene derivatives, substituted at the wider rim by four urea functions are easily available in great variety. In apolar solvents like benzene or chloroform they dimerize via NH…O=C hydrogen bonds encapsulating a single solvent molecule as guest. The exclusive formation of dimers has been proved in solution by NMR, while their shape has been characterized by single crystal X-ray analysis. The kinetic stability and the rate of the guest exchange have been studied by NOESY experiments using a derivative with lower symmetry.
3-(2-Fluorophenyl)-6-(phenoxymethyl)-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole
2008
The crystal structure of the title compound, C16H11FN4OS, was synthesized in the course of our studies on 1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles as inhibitors of p38 mitogen-activated protein kinase (MAPK). The three-dimensional data obtained were used to generate a three-dimensional pharmacophore model for in silico database screening. The dihedral angles between the central heterocylic system and the fluorophenyl and phenyl rings are 20.21 (3) and 5.43 (1)°, respectively; the dihedral angle between the two benzene rings is 15.80 (4)°.
N-{4-[(3-Methyl-phen-yl)sulfamo-yl]phen-yl}benzamide.
2011
In the title compound, C20H18N2O3S, the dihedral angle between the central benzene ring and the amide group is 24.1 (3)° and that between this ring and the aromatic ring of the tolyl group is 68.2 (16)°. In the crystal, adjacent molecules are linked by N—H...O hydrogen bonds into a linear chain running along [100]. Weak C—H...O contacts also occur. Extensive weak π–π interactions exist from both face-to-face and face-to-edge interactions occur between the aromatic rings [centroid–centroid distances = 3.612 (2) and 4.843 (2) Å].
3-(2,4-Dimethoxyanilino)-8-methoxydibenz[b,e]oxepin-11(6H)-one
2011
In the title compound, C23H21NO5, the two benzene rings of the tricyclic unit are oriented at a dihedral angle of 37.5 (8)°. The 2,4-dimethoxyanilino residue is oriented at a dihedral angle of 60.2 (8)° towards the phenoxy ring. In the crystal, the central carbonyl O atom accepts two hydrogen bonds from the N—H and C—H groups. A further intermolecular C—H...O interaction involving one of the methoxy O atoms is also observed.
3-(2,4-Difluoro-anilino)-9-nitro-dibenzo[b,e]oxepin-11(6H)-one.
2011
In the title compound, C20H12F2N2O4, the two benzene rings of the tricyclic unit are oriented at a dihedral angle of 30.6 (1)°. The 2,4-difluoroanilino residue is oriented at a dihedral angle of 68.2 (1)° with respect to the phenoxy ring. In the crystal, N—H...O hydrogen bonds between the amino group and the carbonyl O atom of the oxepinone ring link the molecules into infinte chains along the c axis.
1-[2-(2,4-Dichlorophenyl)pentyl]-1H-1,2,4-triazole
2009
The title compound, C13H15Cl2N3, also known as penconazole, crystallizes as a racemate. The dihedral angle between the benzene and triazole rings is 24.96 (13)°. In the crystal structure, molecules are linked into chains running parallel to the c axis by intermolecular C—H...N hydrogen-bonding interactions.
Guest-Host Systems of 1,3,5-Tristyrylbenzenes
2003
(E,E,E)-1,3,5-Tris(3,4,5-trimethoxystyryl)benzene (1a) forms monoclinic crystals of the space group P21/c. Incorporation of three transoid diacetyl guest molecules between the three arms leads to triclinic crystals of the space group P1. The styryl groups, originally present in a nonsymmetrical conformation, are simultaneously transformed to a C3 arrangement. (E,E,E)-1,3,5-Tris- (3,4,5-tripropoxystyryl)benzene (1b) forms monoclinic crystals of the space group P21/c. The C3 arrangement of the styryl groups is present in the first, the unsymmetrical arrangement in the second modification. Incorporation of two acetone guests in the largest and the middle-sized angle space between the styryl ar…