scholarly journals 3β-Hydroxy-28-norolea-12,17-dien-11-one

2014 ◽  
Vol 70 (8) ◽  
pp. o842-o842
Author(s):  
Werner Seebacher ◽  
Robert Weis ◽  
Johanna Faist ◽  
Robert Saf ◽  
Ferdinand Belaj
Keyword(s):  
Hydrogen Bonds ◽  
Diffraction Data ◽  
Title Compound ◽  
The Other ◽  
Asymmetric Unit ◽  
Chiral Molecules ◽  
Compound C ◽  
Alkaline Conditions ◽  
The Absolute ◽  
Absolute Structure

The title compound, C29H44O2, was formed by treatment of 11-oxooleanolic acid under strong alkaline conditions. The absolute structure of the chiral molecules could not be determined reliably from the diffraction data, but is known from other triterpenes. The asymmetric unit consists of two molecules, 1 and 2. In both molecules, ringsAandBshow chair conformations. The other rings show mixed forms between envelope and half-chair conformations with atoms in positions 8, 15 and 21 forming the flaps in ringsC,DandE, respectively. RingsDandEof molecule 2 are disordered over two orientations, with occupancies of 0.557 (4) and 0.443 (4), which differ in the direction of the flap in ringE. In the crystal, molecules 1, as well as the molecules 2, are linked by O—H...O hydrogen bonds, forming chains parallel to thebaxis.

scholarly journals 2-[(E)-(2S,5R)-2-Isopropyl-5-methylcyclohexylidene]-N-methylhydrazine-1-carbothioamide

IUCrData ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Adriano Bof de Oliveira ◽  
Johannes Beck ◽  
Jörg Daniels ◽  
Renan Lira de Farias
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Centrosymmetric Dimer ◽  
Polymeric Structure ◽  
Compound C ◽  
Graph Set ◽  
The Absolute ◽  
Absolute Structure

There are two molecules in the asymmetric unit of the title compound, C12H23N3S, which are linked by two strong N—H...S hydrogen bonds, building a non-centrosymmetric dimer with graph-set motifR22(8). The molecules are further connected by N—H...S interactions into a two-dimensional hydrogen-bonded polymeric structure along the [001] direction. The absolute structure is based on the refinement of the Flack parameter.

scholarly journals 2-(1,3-Benzodioxol-5-yl)-1H-benzimidazole

2014 ◽  
Vol 70 (2) ◽  
pp. o157-o157
Author(s):  
Nadir Ghichi ◽  
Mohamed Amine Benaouida ◽  
Ali Benosmane ◽  
Ali Benboudiaf ◽  
Hocine Merazig
Keyword(s):  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Ring System ◽  
The Other ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Compound C ◽  
The Mean ◽  
Independent Molecules

The asymmetric unit of the title compound, C14H10N2O2, contains two independent molecules. In each molecule, the benzodioxole ring system displays an envelope conformation, with the methylene C atom located at the flap deviating by 0.081 (2) and 0.230 (2) Å from the mean plane formed by the other atoms. The dihedral angles between the benzoimidazole ring system (all atoms) and the benzodioxole benzene ring are 15.35 (6) and 10.99 (7)°. In the crystal, molecules are linked by N—H...N hydrogen bonds into chains running along the [101].

(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 1-Methyl-3-(2-methylphenyl)-3a-nitro-1,2,3,3a,4,9b-hexahydrochromeno[4,3-b]pyrrole

2012 ◽  
Vol 68 (6) ◽  
pp. o1735-o1735
Author(s):  
S. Sundaramoorthy ◽  
N. Sivakumar ◽  
M. Bakthadoss ◽  
D. Velmurugan
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Chair Conformation ◽  
The Other ◽  
Asymmetric Unit ◽  
Pyran Ring ◽  
Pyrrolidine Ring ◽  
Π Interactions ◽  
Compound C ◽  
Independent Molecules

The asymmetric unit of the title compound, C19H20N2O3, contains two independent molecules in both of which the pyrrolidine ring adopts an envelope conformation, but with a C atom as the flap in one molecule and the N atom in the other. The pyran ring adopts a half-chair conformation in both molecules. In the crystal, molecules are linked via C—H...O hydrogen bonds and C—H...π interactions.

scholarly journals Crystal structure ofN-carbamothioyl-2-methylbenzamide

2015 ◽  
Vol 71 (6) ◽  
pp. o425-o425 ◽  
Author(s):  
Farook Adam ◽  
Nadiah Ameram ◽  
Wai Mun Tan
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Aromatic Ring ◽  
Dihedral Angle ◽  
Title Compound ◽  
The Other ◽  
Asymmetric Unit ◽  
Compound C

There are two molecules in the asymmetric unit of the title compound, C9H10N2OS. In one, the dihedral angle between the aromatic ring and the carbamothioyl group is 52.31 (7)° and in the other it is 36.16 (6)°. Each molecule features an intramolecular N—H...O hydrogen bond, which generates anS(6) ring and the O and S atoms have anantidisposition. In the crystal, molecules are linked by N—H...S and N—H...O hydrogen bonds, generating separate [130] and [1-30] infinite chains. Weak C—H...O and C—H...S interactions are also observed.

scholarly journals 2,2′-Bis{8-[(benzylamino)methylidene]-1,6-dihydroxy-5-isopropyl-3-methylnaphthalen-7(8H)-one}

2013 ◽  
Vol 69 (11) ◽  
pp. o1626-o1627
Author(s):  
Shukhrat M. Hakberdiev ◽  
Samat A. Talipov ◽  
Davranbek N. Dalimov ◽  
Bakhtiyar T. Ibragimov
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Supramolecular Architecture ◽  
Asymmetric Unit ◽  
Ring Systems ◽  
Compound C ◽  
Phenyl Rings ◽  
Independent Molecules

The asymmetric unit of the title compound, C44H44N2O6, contains two independent molecules with similar conformations. The dihydronaphthalene ring systems are approximately planar [maximum deviations = 0.036 (2), 0.128 (2), 0.0.24 (2) and 0.075 (2) Å]. The dihedral angle between two dihydronaphthalene ring systems is 83.37 (4)° in one molecule and 88.99 (4)° in the other. The carbonyl O atom is linked with the adjacent hydroxy and imino groupsviaintramolecular O—H...O and N—H...O hydrogen bonds. In the crystal, molecules are linked through O—H...O hydrogen bonds into layers parallel to (001), and adjacent layers are further stacked by π–π interactions between dihydronaphthalene and phenyl rings into a three-dimensional supramolecular architecture. In the crystal, one of the isopropyl groups is disordered over two positions with an occupancy ratio of 0.684 (8):0.316 (8).

scholarly journals Crystal structure of 2,4,6-trimethylbenzoic anhydride

2017 ◽  
Vol 73 (11) ◽  
pp. 1735-1738
Author(s):  
Michael A. Land ◽  
Katherine N. Robertson ◽  
Jason A. C. Clyburne
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
The Other ◽  
Asymmetric Unit ◽  
Aromatic Rings ◽  
Rotation Symmetry ◽  
Compound C ◽  
Benzoic Anhydride ◽  
Ether Solution

The title compound, C20H22O3, was formed in the reaction between 2,4,6-trimethylbenzoic acid andN,N-diisopropylethylamine in the presence of 1,3-dichloro-1,3-bis(dimethylamino)propenium hydrogen dichloride, and was recrystallized from diethyl ether solution. It is the first exclusively alkyl-substituted benzoic anhydride to have been structurally characterized. The asymmetric unit consists of a half molecule, the other half of which is generated by twofold rotation symmetry; the dihedral angle between the symmetry-related aromatic rings is 54.97 (3)°. The geometric parameters of the aromatic ring are typical of those for 2,4,6-trimethylphenyl substituted groups. The C=O and C—O bond lengths are 1.1934 (12) and 1.3958 (11) Å, respectively, and the angle between these three atoms (O=C—O) is 121.24 (9)°. In the crystal, molecules are linked by weak C—H...O hydrogen bonds and C—H...π interactions. The packing features wavy chains that extend parallel to [001].

scholarly journals Crystal structure of 1-(4-formylbenzylidene)thiosemicarbazone

2014 ◽  
Vol 70 (9) ◽  
pp. o970-o970 ◽  
Author(s):  
Rosa Carballo ◽  
Arantxa Pino-Cuevas ◽  
Ezequiel M. Vázquez-López
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
The Other ◽  
Asymmetric Unit ◽  
Compound C ◽  
Planar Molecules ◽  
Discrete Networks

The asymmetric unit of the title compound, C9H9N3OS, contains two approximately planar molecules (r.m.s. deviations for 14 non-H atoms = 0.094 and 0.045 Å), with different conformations. In one of them, the C=O group issynto the S atom and in the other it isanti. Each molecule features an intramolecular N—H...N hydrogen bond, which generates anS(5) ring. In the crystal, molecules are linked by N—H...O and N—H...S hydrogen bonds, generating discrete networks; thesynmolecules form [010] chains and theantimolecules form (100) sheets.

scholarly journals Bis[3-methyl-5-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide methanol hemisolvate

2014 ◽  
Vol 70 (2) ◽  
pp. o127-o128
Author(s):  
Maksym Seredyuk ◽  
Natalia O. Sharkina ◽  
Elzbieta Gumienna-Kontecka ◽  
Anatoly A. Kapshuk
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Dihedral Angles ◽  
Supramolecular Architecture ◽  
Asymmetric Unit ◽  
Compound C ◽  
Independent Molecules ◽  
Solvent Molecules

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.

scholarly journals Crystal structure of allylammonium hydrogen succinate at 100 K

2014 ◽  
Vol 70 (9) ◽  
pp. o917-o918 ◽  
Author(s):  
Błażej Dziuk ◽  
Bartosz Zarychta ◽  
Krzysztof Ejsmont
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Torsion Angle ◽  
Title Compound ◽  
The Other ◽  
Dihedral Angles ◽  
Asymmetric Unit ◽  
Compound C

The asymmetric unit of the title compound, C2H8N+·C4H5O4−, consists of two allylammonium cations and two hydrogen succinate anions (Z′ = 2). One of the cations has a near-perfectsyn-periplanar (cis) conformation with an N—C—C—C torsion angle of 0.4 (3)°, while the other is characterized by agaucheconformation and a torsion angle of 102.5 (3)°. Regarding the anions, three out of four carboxilic groups are twisted with respect to the central C–CH2–CH2–C group [dihedral angles = 24.4 (2), 31.2 (2) and 40.4 (2)°], the remaining one being instead almost coplanar, with a dihedral angle of 4.0 (2)°. In the crystal, there are two very short, near linear O—H...O hydrogen bonds between anions, with the H atoms shifted notably from the donor O towards the O...O midpoint. These O—H...O hydrogen bonds form helical chains along the [011] which are further linked to each other through N—H...O hydrogen bonds (involving all the available NH groups), forming layers lying parallel to (100).

Sign in / Sign up

Export Citation Format

Share Document