The structure of 1,2,4,4,6-pentaphenyl-1,4-dihydropyridine

1990 ◽  
Vol 55 (8) ◽  
pp. 2059-2065 ◽  
Author(s):  
Jaroslav Vojtěchovský ◽  
Jindřich Hašek ◽  
Jiří Ječný ◽  
Karel Huml
Keyword(s):  
Title Compound ◽  
Cambridge Structural Database ◽  
Boat Conformation ◽  
Planar Conformation ◽  
Structural Database ◽  
Independent Molecules ◽  
Dihydropyridine Ring

Title compound is triclinic, Mr = 461.60; P1, a = 9.158(1), b = 16.062(3), c = 19.472(3) Å, α = 110.69(1)°, β = 89.70(1)°, γ = 103.17(1)°, V = 2 600(1) Å3, Z = 4, Do = 1.15(3), Dc = 1.179(1) Mg m-3, λ(CuKα) = 1.5418 Å, μ = 0.509 mm-1, F(000) = 976 K, R = 0.040 for 8 059 unique observed reflections. Both symmetrically independent molecules show a different geometry of the 1,4-dihydropyridine ring: either the boat conformation with apexes C(sp3), N and boat angles 14.7(3)° and 10.3(2)° respectively, or the planar conformation. The conformation has been compared with similar dihydropyridines obtained from Cambridge Structural Database.

scholarly journals 2,6-Diamino-4-(4-chlorophenyl)-1-methyl-1,4-dihydropyridine-3,5-dicarbonitrile

2014 ◽  
Vol 70 (7) ◽  
pp. o812-o813 ◽  
Author(s):  
Michael Purushothaman ◽  
Kaliyaperumal Thanigaimani ◽  
Suhana Arshad ◽  
Sekar Silambarasan ◽  
Ibrahim Abdul Razak ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Boat Conformation ◽  
Compound C ◽  
Dihydropyridine Ring

In the title compound, C14H12ClN5, the dihydropyridine ring adopts a shallow boat conformation. The dihedral angle between the plane of this ring and that of the chlorobenzene ring is 69.15 (15)°. In the crystal, molecules are linked by N—H...N and N—H...Cl hydrogen bonds, generating (001) sheets.

scholarly journals (1R,4R,6S,7R)-5,5-Dibromo-1,4,8,8-tetramethyltricyclo[5.4.1.04,6]dodecan-12-one

2014 ◽  
Vol 70 (5) ◽  
pp. o526-o526 ◽  
Author(s):  
Mohamed Zaki ◽  
Ahmed Benharref ◽  
Jean-Claude Daran ◽  
Moha Berraho
Keyword(s):  
Title Compound ◽  
Chair Conformation ◽  
Membered Ring ◽  
The Other ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Cedrus Atlantica ◽  
Compound C ◽  
Independent Molecules

The title compound, C16H24Br2O, was synthesized from the reaction of β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from Atlas cedar (Cedrus atlantica). The asymmetric unit contains two independent molecules with similar conformations. Each molecule is built up from two fused seven-membered rings and an additional three-membered ring. In both molecules, one of the seven-membered rings has a chair conformation, whereas the other displays a screw-boat conformation.

(1R,4S,8R,12S,13S,14R,16S,19R)-14-Hydroxy-7,7-dimethyl-17-methylene-2,9,18-trioxo-3,10-dioxapentacyclo[14.2.1.01,13.04,12.08,12]nonadec-19-yl acetate

2007 ◽  
Vol 63 (11) ◽  
pp. o4439-o4439
Author(s):  
Hao Shi
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Absolute Configuration ◽  
Title Compound ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Compound C ◽  
Independent Molecules ◽  
The Absolute

The title compound, C22H26O8, prepared from the natural diterpenoid Macrocalyxin J, is built up from five fused rings. Cyclohenane ring A adopts a chair conformation, ring B exists in a screw-boat conformation and ring C adopts a boat conformation; the two five membered rings adopt envelope conformations. Two unique molecules are present in the asymmetric unit; both independent molecules have the same absolute configuration, the absolute configuration being deduced from the chirality of Macrocalyxin A, which was isolated from the same plant (i.e. Rabdosia macrocalyx) as Macrocalyxin J. The crystal structure displays intermolecular O—H...O hydrogen bonds.

scholarly journals 2-Amino-6-{[(6-chloropyridin-3-yl)methyl](ethyl)amino}-1-methyl-5-nitro-4-phenyl-1,4-dihydropyridine-3-carbonitrile ethanol monosolvate

2012 ◽  
Vol 68 (4) ◽  
pp. o1146-o1146
Author(s):  
Chuan-Wen Sun ◽  
Yan-Xia Chen ◽  
Tian-Yan Liu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Boat Conformation ◽  
Methyl Ethyl ◽  
Compound C ◽  
Dihydropyridine Ring

In the title compound, C21H21ClN6O2·C2H6O, a member of the insecticidal active neonicotinoid group of compounds, the 1,4-dihydropyridine ring adopts a boat conformation. An intramolecular C—H...O hydrogen bond occurs while the components are linked by an N—H...O interaction. The crystal packing is stablized by O—H...N hydrogen bonds and C—H...O interactions.

Non-centrosymmetric racemates: space-group frequencies and conformational similarities between crystallographically independent molecules

2000 ◽  
Vol 56 (4) ◽  
pp. 715-719 ◽  
Author(s):  
Bjørn Dalhus ◽  
Carl Henrik Görbitz
Keyword(s):  
Cambridge Structural Database ◽  
Asymmetric Unit ◽  
Space Group ◽  
Space Groups ◽  
Common Space ◽  
Molecular Superposition ◽  
Structural Database ◽  
The Common ◽  
The Mean ◽  
Independent Molecules

DL-Allylglycine (DL-2-amino-4-pentenoic acid, C5H9NO2) yields crystals with Pca21 symmetry and two crystallographically independent yet pseudo-inversion-related enantiomers. The distribution among the common space groups of other crystalline racemates with more than one molecule in the asymmetric unit has been established. The conformational similarities between crystallographically independent enantiomers in 114 non-centrosymmetric racemates were quantified using the r.m.s. deviation for a molecular superposition. The analysis shows that in the majority of crystals the conformations of the crystallographically independent molecules are very similar with mean r.m.s. deviation = 0.190 Å. In almost 80% of the structures the mean r.m.s. deviations is in the interval 0–0.2 Å. It is estimated that racemates constitute 23% of the centrosymmetric organic structures in the Cambridge Structural Database.

scholarly journals (1S,2R,8R)-11-Amino-2,2-dichloro-3,7,7,10-tetramethyltricyclo[6.4.0.01,3]dodec-10-en-9-one

IUCrData ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Mustapha Ait Elhad ◽  
Ahmed Benharref ◽  
Lahcen El Ammari ◽  
Mohamed Saadi ◽  
Abdelouahd Oukhrib ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Membered Ring ◽  
Monoclinic Space Group ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Space Group ◽  
Axis Direction ◽  
Compound C ◽  
Independent Molecules

The title compound, C16H23Cl2NO, crystallizes in the monoclinic space groupP21with two independent molecules (AandB) in the asymmetric unit. They have essentially the same conformation. Each molecule is built up from fused six- and seven-membered rings and an additional three-membered ring. The six-membered ring has an envelope conformation, with the C atom belonging to the three-membered ring forming the flap, while the seven-membered ring displays a boat conformation. In the crystal, molecules are linked into chains propagating along thea-axis direction by N—H...O hydrogen bonds.

scholarly journals 5-[(3,4-Dimethoxybenzyl)aminomethylene]-2,2-dimethyl-1,3-dioxane-4,6-dione

2009 ◽  
Vol 65 (6) ◽  
pp. o1298-o1299
Author(s):  
Rui Li ◽  
Jian-You Shi ◽  
Zhen-Yu Ding ◽  
Yu-Quan Wei ◽  
Jian Ding
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Dihedral Angles ◽  
Boat Conformation ◽  
Compound C ◽  
Planar Conformation ◽  
Planar Part ◽  
Dioxane Ring

The title compound, C15H17NO6, is approximately planar, with dihedral angles of 3.11 (4) and 2.12 (4)° between the connecting aminomethylene unit and the planar part of the dioxane ring, and between the dimethoxybenzyl ring and the aminomethylene group, respectively. The dioxane ring exhibits a half-boat conformation, in which the C atom between the dioxane O atoms is 0.5471 (8) Å out of the plane. The molecule has an intramolecular N—H...O hydrogen bond which may stabilize the planar conformation. In the crystal, weak intermolecular C—H...O hydrogen-bonding contacts, result in the formation of sheets parallel to theabplane.

scholarly journals N,N′-Bis(4-bromophenyl)-N,N′-dimethylurea

IUCrData ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Alexandre Pocinho ◽  
Sonia Mallet-Ladeira ◽  
Christelle Hureau ◽  
Emmanuel Gras
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Cambridge Structural Database ◽  
Halogen Bonds ◽  
Aromatic Rings ◽  
Compound C ◽  
Structural Database

The structure of the title compound, C15H14Br2N2O, at 180 K has monoclinic (P21/n) symmetry. It was obtained unexpectedly from the decomposition of the parent 4-bromo-N-tert-butoxycarbonyl-N-methyl-aniline. It exhibits an `endo' conformation with angles between the two aromatic rings slightly lower than the average values found for similar compounds on the Cambridge Structural Database. In the crystal, C—H...O hydrogen bonds and short Br...Br halogen bonds [3.444 (1) Å] are observed.

Two newXP(O)[NHC(CH3)3]2phosphoramidates, withX= (CH3)2N and [(CH3)3CNH]2P(O)(O)

2012 ◽  
Vol 68 (4) ◽  
pp. o164-o169 ◽  
Author(s):  
Mehrdad Pourayoubi ◽  
Atekeh Tarahhomi ◽  
Fatemeh Karimi Ahmadabad ◽  
Karla Fejfarová ◽  
Arie van der Lee ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Asymmetric Unit ◽  
Structural Database ◽  
Independent Molecules ◽  
Hydrogen Bond Patterns

InN,N′-di-tert-butyl-N′′,N′′-dimethylphosphoric triamide, C10H26N3OP, (I), andN,N′,N′′,N′′′-tetra-tert-butoxybis(phosphonic diamide), C16H40N4O3P2, (II), the extended structures are mediated by P(O)...(H—N)2interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H—N)2hydrogen bonds, givingR21(6) loops and forming two independent chains parallel to theaaxis. Of the 12 independenttert-butyl groups, five are disordered over two different positions with occupancies ranging from 1 \over 6 to 5 \over 6. In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H—N)2hydrogen bonds giveS(6) andR22(8) rings, and the molecules form extended chains parallel to thecaxis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)2and (NH)2P(O)(O)P(O)(NH)2skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen-bond patterns in these families of phosphoramidates. The strengths of P(O)[...H—N]x(x= 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)2P(O)(NH) and P(O)(NH)3fragments.

scholarly journals Diethyl 4-(4-acetamidophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

2012 ◽  
Vol 68 (8) ◽  
pp. o2536-o2536
Author(s):  
Yiliang Zhao ◽  
David E. Hibbs ◽  
Paul W. Groundwater ◽  
Abram Wassef
Keyword(s):  
Hydrogen Bonding ◽  
Microwave Irradiation ◽  
Title Compound ◽  
Ethyl Acetoacetate ◽  
Boat Conformation ◽  
Compound C ◽  
Dihydropyridine Ring

The title compound, C21H26N2O5, was unexpectedly obtained as a by-product in the reaction of ethyl acetoacetate, 4-acetamidobenzaldehyde and urea under microwave irradiation. The dihydropyridine ring assumes a flattened boat conformation. Intermolecular N—H...O and weak C—H...O hydrogen bonding occurs in the crystal.

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