Search results for "HYDROGEN"
showing 10 items of 4254 documents
Pimobendan B from powder diffraction data
2013
The title molecule, C19H18N4O2{systematic name: (RS)-6-[2-(4-methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-4,5-dihydropyridazin-3(2H)-one}, adopts an extended conformation. The dihedral angles between the central benzimidazole ring sytem and the pendant methoxyphenyl and pyridazinone residues are 1.41 (18) and 9.7 (3)°, respectively. In the crystal, N—H...N hydrogen bonds link the imadazole groups into [001] chains, and pairs of N—H...O hydrogen bonds link the pyridazinone groups into dimers. Together, these generate a two-dimensional supramolecular structure parallel to (010). The layers are linked by C—H...π interactions.
Crystal structure of 5-(5,6-dihydrobenzo[4,5]imidazo[1,2-c]quinazolin-6-yl)-2-methoxyphenol
2015
In the molecule of the title compound, C21H17N3O2, the 5,6-dihydrobenzimidazo[1,2-c]quinazoline moiety is disordered over two orientations about a pseudo-mirror plane, with a refined occupancy ratio of 0.863 (2):0.137 (2). The dihedral angles formed by the benzimidazole ring system and the benzene ring of the quinazoline group are 14.28 (5) and 4.7 (3)° for the major and minor disorder components, respectively. An intramolecular O—H...O hydrogen bond is present. In the crystal, molecules are linked by O—H...N hydrogen bonds, forming chains running parallel to [10-1].
1-Benzyl-1H-benzotriazole
2012
In the title compound, C13H11N3, the benzotriazole ring system is essentially planar, with a maximum deviation of 0.0173 (18) Å, and forms a dihedral angle of 75.08 (8)Å with the phenyl ring. In the crystal, pairs of weak C—H...N hydrogen bonds form inversion dimers. In addition, there are weak C—H...π(arene) interactions and weak π–π stacking interactions, with a centroid–centroid distance of 3.673 (11) Å.
1-Benzyl-1H-benzotriazole 3-oxide monohydrate
2012
In the title hydrate, C13H11N3O·H2O, the benzotriazole ring system is planar (r.m.s. deviation = 0.007 Å) and is almost orthogonal to the phenyl ring to which it is linked by a methylene group, forming a dihedral angle of 81.87 (15)°. In the crystal, molecules are linked into chains along [001] by O—H...O hydrogen bonds. The chains are consolidated into a three-dimensional architecture by C—H...O, C—H...π and π–π [centroid–centroid distance between the five- and six-membered rings of the benzotriazole ring system = 3.595 (3) Å] interactions.
1-Mesitylmethyl-1Hbenzotriazole 3-oxide.
2010
In the title compound, C16H17N3O, the benzotriazole ring forms a dihedral angle of 77.25 (6)° with the phenyl ring. The benzotriazole ring is essentially planar with a maximum deviation of 0.012 (19) Å. Weak intermolecular C—H...O hydrogen bonds form R22(10) motifs. The crystal packing is consolidated by π—π interactions with centroid–centroid distances of 3.5994 (12) Å together with very weak C—H...π interactions.
1-Benzyl-1H-benzotriazole 3-oxide-1-hy-droxy-1H-benzotriazole (1/1).
2012
In the title compound, C6H5N3O·C13H11N3O, the benzotriazole ring system in the 1-benzyl-1H-benzotriazole 3-oxide (A) molecule is close to being planar (r.m.s. deviation = 0.011 Å); its mean plane forms a dihedral angle of 67.56 (7)° with that of the attached phenyl ring. The benzotriazole ring system in the 1-hydroxybenzotriazole (B) molecule is also close to being planar (r.m.s. deviation = 0.010 Å). In the crystal, weak C—H...O and C—H...π interactions are present. TheAandBmolecules are linked by an O—H...N hydrogen bond.
Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 cell surface hydrophobicity and survival of the cells under adverse environmental condi…
2012
Abstract Changes in the cell surface hydrophobicity (CSH) of probiotic bacteria Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and the survival of these cells were examined in response to varied cultivation conditions and adverse environmental conditions. An inverse linear relationship (P < 0.01) was detected between the CSH of intact L. acidophilus La5 and B. lactis Bb12 and survival of cells subjected to subsequent freezing/thawing, long-term storage or exposure to mineral and bile acids. The observed relationships were supported by significant correlations between the CSH and changes in composition of the cell envelopes (proteins, lipids and carbohydrates) of L. aci…
A full conformational space analysis of bilirubin
2009
Ab initio methods were utilized in a gas-phase systematic conformational search of bilirubin conformers. The whole molecule was divided into four fragments. Most stable conformers of them were employed to build 196 conformers of the complete bilirubin molecule. Initial geometries were optimized using HF/3-21G level of theory and the minimum energy conformers were then reoptimized at B3LYP/6-31G(d) level. Ridge-tile conformer was the most stable one, in perfect agreement with X-ray data. We found that while tetrapyrrole backbone shows some flexibility, propionic acid side chains have a greater influence in bilirubin conformation because they can interact through different hydrogen bond patte…
Full and Partial Agonism of Ionotropic Glutamate Receptors Indicated by Molecular Dynamics Simulations
2011
Ionotropic glutamate receptors (iGluRs) are synaptic proteins that facilitate signal transmission in the central nervous system. Extracellular iGluR cleft closure is linked to receptor activation; however, the mechanism underlying partial agonism is not entirely understood. Full agonists close the bilobed ligand-binding domain (LBD), while antagonists prevent closure; the transmembrane ion channel either opens or stays closed, respectively. Although some bulky partial agonists produce intermediate iGluR-LBD closure, the available crystal structures also imply that the cleft can be shut with certain partial agonists. Recently, we have shown that the iGluR-LBD closure stage can be recreated b…
Automated pre-column derivatization of amines in biological samples with dansyl chloride and with or without post-column chemiluminescence formation …
1999
On-line automation of two different liquid chromatographic procedures, a pre-column derivatization system and a pre- and post-column system, in order to generate chemiluminescence is reported. Dansyl chloride (Dns-Cl) was used as a pre-column reagent to form fluorophores and bis(2,4,6-trichlorophenyl) oxalate (TCPO) and hydrogen peroxide (H2O2) as a post-column reagent to generate chemiluminescence. This procedure is based on the employment of a primary column packed with C18 material inserted in a multi-dimensional assembly for sample clean-up and derivatization with Dns-Cl. The dansyl derivatives formed are transferred and separated in a LiChrospher 100 RP18 analytical column (125 x 4 mm …