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1.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):e64-e65
The crystal structure of the title compound, C8H16N2O3S·2C3H8O, is divided into hydrophobic and hydrophilic layers. Two peptide molecules in the asymmetric unit are related by pseudo‐translational symmetry along the a axis, as are two of the four 2‐propanol molecules. The last two 2‐propanol molecules in the asymmetric unit have different relative orientations and hydrogen‐bond interactions. 相似文献
2.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):o328-o330
The title compound, C20H21N3O3·0.75H2O, crystallizes as exceedingly thin fibers. The crystal packing arrangement is related to those of other hydrophobic dipeptides with phenylalanine residues, but the structure has pseudo‐tetragonal symmetry in an orthorhombic space group with four peptide molecules and three water molecules in the asymmetric unit. 相似文献
3.
Marius Bruvoll Selma Dizdarevic Nina Fimland Jasmina Hafizovic Carl Henrik Grbitz Helen Therese Kalfjs Kristian Vestli Alexander Krivokapic 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(1):o22-o25
The structures of the title dipeptides, C9H18N2O4·0.33H2O, C12H16N2O4 and C8H16N2O4S·0.34H2O, complete a series of investigations focused on l ‐Xaa‐l ‐serine peptides, where Xaa is a hydrophobic residue. All three structures are divided into hydrophilic and hydrophobic layers. The hydrophilic layers are thin for l ‐phenylalanyl‐l ‐serine, rendered possible by an unusual peptide conformation, and thick for l ‐isoleucyl‐l ‐serine and l ‐methionyl‐l ‐serine, which include cocrystallized water molecules on the twofold axes. 相似文献
4.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):o371-o373
The structure of the title compound, C15H22N2O3·2H2O, was derived from data collected on a very thin twinned needle. The peptide molecule is in a rare conformation normally associated with hydrophobic dipeptides that form nanotubes. Nevertheless, the present structure is divided into hydrophobic and hydrophilic layers. 相似文献
5.
Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o730-o732
The side chains of l ‐alanyl‐l ‐methionine hemihydrate, C8H16N2O3S·0.5H2O, form hydrophobic columns within a three‐dimensional hydrogen‐bond network that includes extended polymers of cocrystallized water molecules and Cα—H⋯S interactions. 相似文献
6.
Franois Loiseau Reinhard Neier Gaël Labat Helen Stoeckli‐Evans 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):o636-o638
In the title compound, C9H12Br2O3, a (tetrahydrofuran‐2‐ylidene)acetate, the double bond has the Z form. In the tetrahydrofuran group, the relative configuration of the Br atom in the 3‐position and the methyl group in the 5‐position is anti. The compound crystallizes with two independent molecules per asymmetric unit and, in the crystal structure, the individual molecules are linked to their symmetry‐equivalent molecules by C—H⋯O hydrogen bonds, so forming centrosymmetric hydrogen‐bonded dimers. 相似文献
7.
Arne Johansen Randi Midtkandal Heidi Roggen Carl Henrik Grbitz 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):o198-o200
The valine side chains in the crystal structure of the title compound [systematic name: 2‐(2‐ammonio‐3‐methylbutanamido)‐3‐hydroxypropanoate trihydrate], C8H16N2O4·3H2O, stack along an a axis of 4.77 Å to form hydrophobic columns surrounded by remarkable water/hydroxyl shells. The peptide main chains are connected by hydrogen bonds in two‐dimensional layers. The peptide molecules in each layer are related only by translation, and generate a very rare pattern. This is rendered possible through the formation of the shortest Cα—H·O(carboxylate) interaction ever recorded. 相似文献
8.
Paul D. Robinson Kevin R. Smith Lori A. Vermeulen 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(10):o632-o634
The structure of the title compound, C14H16N2O6S2·2C6H6O2, consists of 2,2′‐(4,4′‐bipyridinium‐1,1′‐diyl)di(ethanesulfonate) molecules (with crystallographically imposed twofold symmetry) that are hydrogen bonded to each other, as well as to hydroquinone molecules, in a complex three‐dimensional motif. The orange color of the crystals is indicative of the donor–acceptor interaction between the electron‐rich hydroquinone π‐donor and the electron‐deficient bipyridinium π‐acceptor. The dihedral angle between the bipyridyl planes is 38.31 (11)°. The distance from the centroid of one of the hydroquinone molecules to the center of the bipyridinium group is 3.653 (3) Å, which is within the range typically observed for molecular complexes exhibiting charge‐transfer characteristics. 相似文献
9.
Nigel L. Pickett Oliver Just Donald G. VanDerveer William S. Rees 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):560-561
The title compound, [GaCl2(C3H10NSi)(C4H8O)], is the tetrahydrofuran‐coordinated monomer of the previously structurally characterized dimer [GaN(H)SiMe3Cl2]2. The title compound consists of discrete monomeric molecules with two crystallographically independent molecules within the unit cell. The crystal structure is composed of a Ga atom in a four‐coordinate tetrahedral arrangement, with Ga—N distances of 2.025 (3) and 2.026 (3) Å in the two independent molecules. 相似文献
10.
Lilianna Chciska Diana Frster Wolfgang Morgenroth Peter Luger 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):o454-o457
The low‐temperature crystal and molecular structure analyses of two modifications of l ‐alanyl‐l ‐tyrosyl‐l ‐alanine with water, C15H21N3O5·2.63H2O [(I), at 9 K], and ethanol, C15H21N3O5·C2H5O [(II), at 20 K], solvent molecules in the crystal lattice show that the overall conformations of both modifications of the title tripeptide are practically the same. Moreover, despite the presence of different solvent molecules in the crystal lattice, the specific intermolecular interactions characteristic for individual tripeptide molecules of (I) and (II) are conserved. The crystal packing of the two modifications of Ala‐Tyr‐Ala differ from each other only in the solvent region. The tight arrangements of tripeptide molecules seem to be responsible for similar displacement parameters for all non‐H atoms, despite the different distances from the molecular centre of mass. Comparison of the displacement parameters between the room‐ and low‐temperature structures shows that an average Ueq value decrease of about 80% takes place at 9 K [for (I)] and 20 K [for (II)] with respect to room temperature. 相似文献
11.
Damon A. Parrish A. Alan Pinkerton 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(2):o80-o82
The title solvate of the steroid 17β‐estradiol (E2) with methanol and water, C18H24O2·0.67CH4O·0.33H2O, is the first E2 derivative to contain three crystallographically independent molecules in the asymmetric unit. The three steroid molecules, along with two methanol molecules and a water molecule, create a three‐dimensional hydrogen‐bonded system. Three‐sided columns are formed, with the estradiol molecules aligned lengthwise parallel to (101), and joined by solvent molecules at both hydrophilic ends. The three estradiol molecules differ slightly in their ring‐bowing angles, i.e. the angle between the mean plane of the A ring and that of the BCD ring; this angle ranges from 7.1 to 12.2°. 相似文献
12.
Canan Kazak Veysel T. Yilmaz Suleyman Servi Murat Koca Frank W. Heinemann 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(6):o348-o350
The title compounds, 1,3‐dibenzoylimidazolidine‐2‐thione, C17H14N2O2S, (I), and 1,3‐dibenzoyl‐3,4,5,6‐tetrahydropyrimidine‐2(1H)‐thione, C18H16N2O2S, (II), were obtained from the reactions of imidazolidine‐2‐thione and 1,4,5,6‐tetrahydropyrimidine‐2‐thiol, respectively, with benzoyl chloride. Compounds (I) and (II) contain, respectively, imidazolidinethione [C=S = 1.6509 (14) Å] and pyrimidinethione [C=S = 1.6918 (19) Å] moieties bonded to two benzoyl rings. The molecules of (I) exhibit C2 symmetry, the C=S bond lying along the twofold rotation axis, while the molecules of (II) have mirror symmetry (Cs). The imidazolidine ring in (I) is essentially planar, while the pyrimidine ring in (II) adopts a boat conformation. Molecules of (I) are linked by weak intermolecular C—H⋯O interactions, while molecules of (II) are held together by van der Waals interactions. 相似文献
13.
Graeme J. Gainsford Peter C. Tyler Richard H. Furneaux 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):e394-e395
The title compound (alternatively 1,7,8‐triacetoxyperhydroindolizin‐6‐yl benzoate), C21H25NO8, was obtained during studies of castanospermine derivatives. The crystal structure consists of independent molecules with only van der Waals contacts. The fused six‐ and five‐membered rings adopt chair and twist conformations, respectively. 相似文献
14.
Tali Lavy Yana Sheynin Moshe Kapon Menahem Kaftory 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o50-o53
The crystal structures of three 1:2 inclusion compounds that consist of host molecule 2,5‐diphenylhydroquinone (C18H14O2) and the guest molecules 2‐pyridone (C5H5NO), 1,3‐diphenyl‐2‐propen‐1‐one (chalcone, C15H12O) and 1‐(4‐methoxyphenyl)‐3‐phenyl‐2‐propen‐1‐one (4′‐methoxychalcone, C16H14O2) were determined in order to study the ability of guest molecules in inclusion compounds to undergo photoreaction. All of the crystals were found to be photoresistant. The three inclusion compounds crystallize in triclinic space group . In each case, the host/guest ratio is 1:2, with the host molecules occupying crystallographic centers of symmetry and the guest molecules occupying general positions. The guest molecules in each of the inclusion compounds are linked to the host molecules by hydrogen bonds. In the inclusion compound where the guest molecule is pyridone, the host molecule is disordered so that the hydroxy groups are distributed between two different sites, with occupancies of 0.738 (3) and 0.262 (3). The pyridone molecules form dimers via N—H⋯O hydrogen bonds. 相似文献
15.
Joe D. Sauer Hassan Y. Elnagar Frank R. Fronczek 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(2):o62-o64
Crystalline N,N‐dimethyl‐n‐tetradecylamine oxide has been prepared by reaction of liquid N,N‐dimethyl‐n‐tetradecylamine with 70% H2O2 in the presence of CO2 as catalyst. The resulting soft low‐melting solid was crystallized as the dihydrate, viz. C16H35NO·2H2O. The extended hydrocarbon chains pack in a parallel fashion, with the N‐oxide ends of the molecules forming hydrogen bonds with the water molecules in hydrophilic layers. The N—O distance is 1.411 (3) Å. 相似文献
16.
Viktor Vrbel Jozef Lehotay Drahomír Oktavec tefan Marchalín 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1073-1074
The crystal structure of the title compound, C20H23N3O7, consists of relatively isolated molecules. The substituted 1,4‐dihydropyridine ring adopts a flattened boat conformation. Both ester groups, at positions 3 and 5, have cis,cis geometry. The phenyl ring is nearly planar and is approximately perpendicular to the 1,4‐dihydropyridine ring (dihedral angle 87.70°). 相似文献
17.
Boris Shivachev Rosica Petrova Emilia Naydenova 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(8):o524-o526
The title compound [systematic name: 1′‐aminocyclohexanespiro‐4′‐imidazole‐2′,5′(3′H,4′H)‐dione], C8H13N3O2, has been synthesized and was found to crystallize in two different structures, both monoclinic and both with the same P21/c space group. In the first structure, there are two molecules in the asymmetric unit, one of which uses all of its hydrogen‐bond donors and acceptors and forms undulating layers, while the other forms chains propagating perpendicular to the layers. In the second structure, there is only one independent molecule and the packing is based on a chain structure mediated by hydrogen bonding between the hydantoin moieties and further grouped into hydrophilic layers separated by layers of the hydrophobic cyclohexyl groups. 相似文献
18.
John Nicolson Low Justo Cobo Braulio Insuasty Henry Insuasty Manuel Nogueras Adolfo Snchez 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o103-o105
In both title compounds, i.e. 3‐methyl‐1,5‐diphenyl‐1,6,7,8‐tetrahydropyrazolo[3,4‐b][1,4]diazepine, C19H18N4, (I), and 5‐(4‐chlorophenyl)‐3‐methyl‐1‐phenyl‐1,6,7,8‐tetrahydropyrazolo[3,4‐b][1,4]diazepine, C19H17ClN4, (II), an N—H?N hydrogen bond links six molecules to form an R(30) ring. Compound (I) crystallizes in the R space group and (II) crystallizes in P with three molecules in the asymmetric unit. The molecule of (I) contains a disordered seven‐membered ring. 相似文献
19.
Michael Wiebcke Jürgen Felsche 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):1050-1052
In the title compound, tetraethylammonium hydroxide pentahydrate, C8H20N+·OH?·5H2O, layers of approximately hexagonally close‐packed NEt4+ cations and anionic layers of hydroxide and water molecules are stacked alternately along the b axis. All hydroxide and water H atoms are in ordered positions, giving rise to a network of hydrogen bonds [O?O 2.633 (1)–2.947 (2) Å] with four‐ and six‐membered rings. The hydroxide ion accepts four hydrogen bonds from four water molecules but does not act as a proton donor. 相似文献
20.
Nobuo Okabe Yoko Eguchi Junko Miura Shimosaki Akiko 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):e416-e417
In the structure of the title compound, 2‐(3‐ammonio‐3‐carboxypropanoyl)‐1‐anilinium sulfate dihydrate, C10H14N2O32+·SO42?·2H2O, the two amino groups are protonated. The molecule has a trans planar zigzag carbon‐skeletal conformation elongated nearly in the benzene ring plane. The two amino and the carboxyl groups are located on the same side of the molecule. The crystal structure is stabilized by intermolecular hydrogen bonds involving the water molecules and the sulfate ion. 相似文献