Search results for "angle"
showing 10 items of 1921 documents
Analyse expérimentale et numérique du comportement de véhicules terrestres en présence d'un vent latéral instationnaire
2013
The automotive manufacturers are nowadays more and more interested in crosswind aerodynamics. Indeed, the driver is subjected every day to strong side air flows, for example when overtaking another vehicle or when passing through a lateral wind wall, generated by terrain topography (as in the case of the passage near the empty space between two buildings).The aerodynamic efforts generated in these situations can lead to undesired lateral deviations,which can be dramatic if the driver is surprised. Different experimental studies, reproducing the effects of a dynamic yaw angle, pointed out the issues of the steady methods, commonly used to qualify the vehicle crosswind behaviour. Little is st…
Structural effects of macrocyclic compounds and their partition in sodium dodecylsulphate aqueous solutions
2003
The partition of 1,4,7,10,13,16-esaoxacyclooctadecane (18C6), 4,7,13,16-tetraoxa-1,10-diazacyclooctadecane (2.2), 2,5,8,11,14,17-esaoxabicyclo[16.4.0]dicosane (B18C6) and 2,5,8,15,18,21-esoxatricyclo[20.4.0.09.14]esacosane (Cy218C6) in sodium dodecyl sulfate (SDS) aqueous solutions and their effect on the structure of surfactant aggregates has been investigated by small-angle neutron scattering. Results from data analysis have shown that by increasing macrocycle concentration the SDS micelles dimensions reduce for all systems investigated. At the same time information on macrocycles partition between the micellar and the continuous phase have been obtained. It was found that an appreciable …
1,1′-[2,3,5,6-Tetramethyl-p-phenylenebis(methyleneoxy)]di-1H-benzotriazole
2009
The complete molecule of the title compound, C(24)H(24)N(6)O(2), is generated by a crystallographic inversion centre. The benzotriazole rings form dihedral angles of 2.10 (7)° with the central aromatic ring. The crystal packing is consolidated by π-π inter-actions, with centroid-centroid distances of 3.6234 (10) Å, together with weak C-H⋯π inter-actions.
1,2-Bis(methylsulfanyl)-1,2-dicarba-closo-dodecaborane(12)
2004
3 pages, 1 figure, 2 tables
Bis[3-methyl-5-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide methanol hemisolvate
2014
The asymmetric unit of the title compound, C18H16N6Se·0.5CH3OH, contains two independent molecules of bis[3-methyl-5-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide with similar C—Se—C bond angles [99.30 (14) and 98.26 (13)°], and a methanol molecule of solvation. In one molecule, the dihedral angles between pyrazole and neighbouring pyridine rings are 18.3 (2) and 15.8 (2)°, and the corresponding angles in the other molecule are 13.5 (2) and 8.3 (2)°. In the crystal, the selenide and solvent molecules are linked by classical O—H...N and N—H...N hydrogen bonds, as well as by weak C—H...O and C—H...π interactions, forming a three-dimensional supramolecular architecture.
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.
The Synthesis and Structure of Palladium 2,4-dimethyl-8-hydroselenoquinolinate
2014
The internal complex palladium 2,4-dimethyl-8- hydroselenoquinolinate Pd[C9H4(CH3)2NSe]2 (I) has been synthesized in the course of study of the complexing activity of 8- hydroselenoquinoline and investigation of the nature of chemical bond metal-selenium in the five-membered metal-containing ring. X-ray diffraction data for I: Monoclinic, space group P21/n, a = 9.0092(4), b = 16.3290(7), c = 14.1073(6) A, = 106.710(2)o, V = 1987.7(2) A3, Z = 4, R1=0.0477, wR2=0.1182 for 4499 reflections (diffractometer Bruker-Nonius KappaCCD, MoK). The crystal structure of the complex I is formed by neutral asymmetric molecules Pd[C9H4(CH3)2NSe]2 in which the central atom palladium is connected bidentic…
3-(4-Fluorophenyl)-6-methoxy-2-(4-pyridyl)quinoxaline
2009
In the title compound, C20H14FN3O, the quinoxaline system makes dihedral angles of 32.38 (7) and 48.04 (7)° with the 4-fluorophenyl and pyridine rings, respectively. The 4-fluorophenyl ring makes a dihedral angle of 57.77 (9)° with the pyridine ring. In the crystal, the molecules form dimeric C—H...N hydrogen-bonded R22(20) ring motifs lying about crystallographic inversion centers. The dimeric units stack via π–π interactions between methoxyphenyl rings and pyridine–fluorophenyl rings with centroid–centroid distances of 3.720 (1) and 3.823 (1) Å, …
1-[2-(Benzylamino)-4-pyridyl]-2-(4-fluorophenyl)ethane-1,2-dione
2009
The crystal structure of the title compound, C20H15FN2O2, contains two crystallographically independent molecules, which are related by a pseudo-inversion center and linked into dimersviaintermolecular N—H...N hydrogen bonds. The 4-fluorophenyl ring of moleculeAmakes dihedral angles of 17.17 (16) and 62.25 (15)°, respectively, with the phenyl and pyridine rings. The 4-fluorophenyl ring of moleculeBmakes dihedral angles of 8.50 (16) and 64.59 (15)°, respectively, with the phenyl and pyridine rings. The dihedral angle between the pyridine ring and the phenyl ring of moleculeA[60.97 (15)°] is bigger than in moleculeB[59.49 (15)°]. The dihedral angle between the two pyridine rings is 1.37 (14)°…
N-(5-Amino-1H-1,2,4-triazol-3-yl)pyridine-2-carboxamide
2013
The title compound, C8H8N6O, was obtained by the reaction of 3,5-diamino-1,2,4-triazole with ethyl 2-picolinate in a glass oven. The dihedral angles formed between the plane of the amide group and the pyridine and triazole rings are 11.8 (3) and 5.8 (3)°, respectively. In the crystal, an extensive system of classical N—H...N and N—H...O hydrogen bonds generate an infinite three-dimensional network.