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In the title compound, C27H20NO3P, the P atom exhibits a somewhat distorted PNO3 tetra-hedral geometry, with the O - P - O angle for the binaphthyl fragment being 102.82 (6)°. The dihedral angle between the naphthyl ring systems is 59.00 (2)°. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R22(8) loops..

1,2,3-Triazolophanes are a class of cyclophanes that has attracted enormous attention in recent times. With the advent of the intramolecular copper-mediated alkyne azide cycloaddition (CuAAC) reaction 1,2,3-triazolophanes of various molecular structure and supramolecular architecture have been synthesized. 1,2,3-Triazolophanes find a variety of applications as molecular hosts, ion sensors, peptidomimics, and supramolecular building blocks, among others. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The molecules of the title compound, C15H14N 2O3, possesses crystallographically imposed twofold rotational symmetry, so the asymmetric unit contains one half-molecule. The fused-ring system deviates significantly from planarity; the planes of the five- and six-membered rings are twisted with respect to each other by 3.0 (1)°. In the crystal, weak C - H⋯O hydrogen bonds link molecules related by translation in [010] into chains. © Haridharan and Ramkumar 2013.

In the title compound, C19H12F6O, a monoketone derivative of curcumin, both double bonds have a trans conformation. The molecule is mostly planar with all C and O atoms essentially coplanar, with the exception of one benzene ring, which is tilted by 17.18 (1)° with respect to the plane of the remainder of the molecule. The r.m.s. deviation from planarity of the coplanar section is 0.0097 Å. The crystal packing features weak C - H⋯O and C - H⋯F interactions.

The title compound, C31H24F4N2O, exists in a chair-boat conformation with an equatorial orientation of the 2-fluorophenyl groups on both sides of the secondary amino group of the chair form. The benzene rings in the 'chair' part are inclined to each other at 19.4 (1)°, while the equivalent angle between the benzene rings in the 'boat' part is 75.6 (1)°. One F atom was treated as disordered over two positions in a 0.838 (4):0.162 (4) ratio. In the crystal, N - H⋯O hydrogen bonds link the molecules into chains along [001] and these chains are held together via weak N - H⋯F and C - H⋯F interactions.

In the title compound, C38H31Cl4N 3O·C3H6O, the 3,7-diaza-bicycle exists in a chair-boat conformation. The 4-chloro-phenyl groups attached to the chair form are equatorially oriented at an angle of 18.15 (3)°with respect to each other, whereas the 4-chloro-phenyl groups attached to the boat form are oriented at an angle of 32.64 (3)°. In the crystal, molecules are linked by N - H⋯π and C - H⋯O inter-actions. © Park et al. 2012.

The title compound, C25H29Br2NO, is a tert-pentyl analog of 2,4-bis(2-bromophenyl)-3-azabicyclo[3.3.1]nonan-9-one [Parthiban et al. (2008). Acta Cryst. E64, o2385]. Similar to its analog, the title compound exists in a twin-chair conformation with an equatorial orientation of the 2-bromophenyl groups. The benzene rings are inclined to each other at a dihedral angle of 29.6 (3)°. The tert-pentyl group on the cyclohexanone ring also adopts an exocyclic equatorial disposition.

The crystal structure of the title compound, C25H 31NO3, exists in a twin-chair conformation with an equatorial orientation of the ortho-eth-oxy-phenyl groups. According to Cremer and Pople [Cremer & Pople (1975), J. Am. Chem. Soc. 97, 1354-1358], both the piperidone and cyclo-hexa-none rings are significantly puckered with total puckering amplitutdes Q T of 0.5889 (18) and 0.554 (2) Å, respectively. The ortho-eth-oxy-phenyl groups are located on either side of the secondary amino group and make a dihedral angle of 12.41 (4)° with respect to each other. The methyl group on the cyclo-hexa-none part occupies an exocyclic equatorial disposition. The crystal packing is stabilized by weak van der Waals inter-actions.

The asymmetric unit of the title compound, C24H29NO3, contains two independent molecules, which each exibit a twin-chair conformation with an equatorial orientation of the ortho-ethoxyphenyl groups but different dihedral angles [41.3 (1) and 24.1 (1)°] between the benzene rings. In the crystal, pairs of weak C-H⋯O hydrogen bonds link the two different independent molecules into dimers.

In the title compound, C28H37NO3, a crystallographic mirror plane bisects the molecule (one half-molecule in the asymmetric unit). The title compound exists in a twin-chair conformation with an equatorial orientation of the 4-butoxyphenyl groups. Both sides of the secondary amino group carry the 4-butoxyphenyl groups at an angle of 38.54 (3)° with respect to one another.

In the title compound, C25H30NO3, a crystallographic mirror plane bisects the molecule. Although it is a positional isomer of 2,4-bis(4-ethoxyphenyl)-7-methyl-3-azabicyclo[3.3.1]non-an-9-one [C25H31NO3, Mr = 393.51; Park et al. (2012c). Acta Cryst. E68, o779-780], its molecular weight is 392.50 due to the 50:50 ratio of the methyl group at bridgehead C atoms. However, the title compound exists in the same twin-chair conformation as its 7-methyl isomer. Also, the 4-ethoxyphenyl groups are equatorially oriented on the bicycle as in its isomer. In the title compound, the cyclohexanone ring deviates from an ideal chair (total puckering amplitude QT = 0.5390 Å) and the piperidone ring is closer to an ideal chair (QT = 0.6064 Å). These QT values are very similar to those of its isomer. Even though a center of symmetry passes through the 7-methyl analog, the benzene rings are oriented 26.11 (3)° with respect to each other, whereas the orientation is 53.10 (3)° for the title compound. The title compound exhibits intermolecular N - H···O interactions [H·· ·A = 2.25 (2) Å, versus 2.26 (2) Å for the analog].

The title compound, C24H29NO3, exists in a twin-chair conformation with an equatorial orientation of the 4-ethoxy-phenyl groups. The benzene rings are inclined to each other at an angle of 28.0 (1)°. In the crystal, weak C - H···O interactions link molecules related by translation into chains along the b axis. The crystal packing exhibits π-π interactions between the benzene rings of neighbouring molecules [centroid-centroid distance = 3.692 (3)Å].

The mol-ecule of the title compound, C 25H 31NO 3, exists in a twin-chair conformation with an equatorial orientation of the 4-eth-oxy-phenyl groups, as observed for its ortho isomer [Parthiban, Ramkumar, Park & Jeong (2011b ), Acta Cryst. E67, o1475-o1476]. The methyl and 4-eth-oxy-phenyl groups are also equatorially oriented on the bicycle, as in the ortho analogue. In particular, although the cyclo-hexa-none ring deviates from an ideal chair, the piperidone ring is closer to an ideal chair, whereas in the ortho isomer both rings are significantly puckered and deviate from ideal chairs. The 4-eth-oxy-phenyl groups on both sides of the secondary amine group are oriented at an angle of 26.11 (3)° with respect to each other, but the 2-eth-oxy-phenyl groups in the ortho isomer are oriented by less than half this [12.41 (4)°]. In contrast to the absence of any significant inter-actions in the crystal packing of the ortho isomer, the title compound features N - H⋯O inter-actions, linking the mol-ecules along the b axis.

In the title compound, C 26H 33NO 3, a crystallographic mirror plane bisects the mol-ecule (two C atoms, one O atom and one N atom lie on the mirror plane). The molecule exists in a twin-chair conformation with equatorial orientations of the 4-propoxyphenyl groups. The dihedral angle between the 4-propoxyphenyl groups is 31.58 (3)°.

The piperidin-4-one ring in the title compound, C 26H 26Cl 2N 2O, exists in a chair conformation with equatorial orientations of the methyl and 4-chlorophenyl groups. The C atom bonded to the oxime group is statistically planar (bond-angle sum = 360.0°) although the C - C=N bond angles are very different [117.83 (15) and 127.59 (15)°]. The dihedral angle between the chloro-phenyl rings is 54.75 (4)°. In the crystal, mol-ecules inter-act via van der Waals forces.

The central ring of the title compound, C 28H 32N 2O 3, exists in a chair conformation with an equatorial disposition of all the alkyl and aryl groups on the heterocycle. The para-anisyl groups on both sides of the secondary amino group are oriented at an angle of 54.75 (4)° with respect to each other. The oxime derivative exists as an E isomer with the methyl substitution on one of the active methyl-ene centers of the mol-ecule. The crystal packing features weak C - H⋯O inter-actions.

In the title compound, C12H14O2S 3, a chain transfer agent (CTA) used in polymerization, the dihedral angle between the aromatic ring and the CS3 grouping is 84.20 (10)°. In the crystal, carboxylic acid inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R22(8) loops.

Nowadays, due to the stringent engine emission norms, an efficient technique is required to reduce oxides of nitrogen (NO X) from automobiles especially from the lean burn engines. Although Urea Selective Catalytic Reduction (SCR) is capable of satisfying these norms, the ammonia slip nullifies its advantages. Ammonia slip is mainly due to the lack of uniformity of ammonia at the monolith entrance. The uniformity of ammonia distribution mainly depends upon the flow parameters of exhaust gas and the injection parameters of urea water solution. The current study addresses the effect of flow parameters, temperature and flow rate of exhaust gas on the injection pressure. The results obtained reveals useful guidelines for enhancing the uniformity of ammonia in Urea-SCR. © (2012) Trans Tech Publications.

Nowadays, due to the stringent engine emission norms, an efficient technique is required to reduce oxides of nitrogen (NOx) from automobiles especially from the lean burn engines. Selective Catalytic Reduction (SCR) is found to be an efficient after treatment method used to reduce oxides of nitrogen (NOx) from the exhaust. However, for light duty vehicles, because of the limited size of the catalysts, ammonia slip nullifies its advantages. Lack of uniformity of ammonia at the SCR monolith entrance causes ammonia slip. This study addresses the effect of injection parameters, location of injector and shape of injector upon the flow parameters, exhaust gas temperature and flow rate. The results obtained from this study provide useful guidelines for optimizing the injection parameters to avoid the ammonia slip. The evaporation of Urea Water Solution (UWS) is also investigated. © 2013 SAE International.