共查询到20条相似文献,搜索用时 31 毫秒
1.
A. Subbiah Pandi D. Velmurugan S. Shanmuga Sundara Raj Hoong‐Kun Fun P. R. Seshadri D. Thirumalai 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):821-824
10‐(4‐Fluorophenyl)‐3,3,6,6,9‐pentamethyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione, C24H28FNO2, (I), crystallizes with two crystallographically independent molecules (which differ slightly in conformation), while 10‐(4‐fluorophenyl)‐9‐propyl‐3,3,6,6‐tetramethyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione, C26H32FNO2, (II), crystallizes with one molecule per asymmetric unit. In both structures, the central ring in the acridine moiety is in a sofa conformation, while the outer rings adopt intermediate half‐chair/sofa conformations. The central pyridine ring is orthogonal to the substituted phenyl ring. In both structures, the packing of the crystal is stabilized by C—H?O intermolecular hydrogen bonds. 相似文献
2.
Andrzej Gzella Danuta Brzda ukasz Koroniak Maria D. Rozwadowska 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o503-o506
In the two title optically active tetrahydroisoquinoline derivatives, namely 3‐hydroxymethyl‐4‐phenyl‐1,2,3,4‐tetrahydroisoquinolin‐2‐ium bromide methanol hemisolvate, C16H18NO+·Br?·0.5CH3OH, (IIb), and 2‐formyl‐3‐hydroxymethyl‐4‐phenyl‐1,2,3,4‐tetrahydroisoquinoline, C17H17NO2, (III), the absolute configurations have been confirmed as 3R,4R by structure refinement using Bijvoet‐pair reflections. The hydroxymethyl and phenyl groups in (IIb) are oriented in equatorial and pseudo‐equatorial positions, respectively, whereas in (III), the corresponding groups are in axial and pseudo‐axial positions, respectively; the hydroxymethyl and phenyl groups are trans with respect to one another in both structures. The heterocyclic rings in (IIb) and (III) adopt envelope conformations inverted with respect to each other. In both structures, the molecules are linked through hydrogen bonds. 相似文献
3.
B. Sivakumar K. SethuSankar U. P. Senthil Kumar R. Jeyaraman D. Velmurugan 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):o153-o155
The title compound, C24H19N3O, crystallizes in the centrosymmetric space group P21/a with one molecule in the asymmetric unit. The tetrahydropyridine ring has a boat conformation. The dihedral angle between the fused pyridine rings is 16.2 (1)°. The equatorial and axial orientations of the two phenyl groups with respect to the tetrahydropyridine ring are confirmed. The nitroso group is coplanar with the attached C—N—C group. The interplanar angle formed between the fused tetrahydropyridine and benzene planes is 13.4 (1)°. The crystal packing is stabilized by an intermolecular C—H⃛O hydrogen bond, which forms a C(9) graph‐set chain running along the [001] direction. 相似文献
4.
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
5.
Peter J. Steel Margaret A. Brimble Brian Hopkins David Rennison 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):o374-o376
The structures of two diastereoisomers of norbormide {systematic name: 5‐[hydroxy(phenyl)(2‐pyridyl)methyl]‐8‐[phenyl(2‐pyridyl)methylene]‐3a,4,7,7a‐tetrahydro‐4,7‐methano‐1H‐isoindole‐1,3(2H)‐dione}, viz. the unsolvated molecule, C33H25N3O3, and the ethyl acetate hemisolvate, C33H25N3O3·0.5C4H8O2, have been determined unambiguously. They differ in the relative stereochemistry about the exocyclic double bond and the relative conformations of the aryl rings. Each compound exhibits both intra‐ and intermolecular hydrogen bonding. 相似文献
6.
John Nicolson Low Justo Cobo Manuel Nogueras Adolfo Snchez Braulio Insuasty Harlen Torres 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o39-o41
2,2‐Dimethyl‐5‐[3‐(4‐methylphenyl)‐2‐propenylidene]‐1,3‐dioxane‐4,6‐dione, C16H16O4, crystallizes in the triclinic space group , with two molecules in the asymmetric unit. These molecules and a centrosymmetrically related pair, linked together by weak C—H?O hydrogen bonds, form a tetramer. 5‐[3‐(4‐Chlorophenyl)‐2‐propenylidene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione, C15H13ClO4, also crystallizes in the triclinic space group , with one molecule in the asymmetric unit. Centrosymmetrically related molecules are linked together by weak C—H?O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C—H?O hydrogen bonds to form a tube which runs parallel to the a axis. 相似文献
7.
The structures of two conformationally similar 1,4‐dihydropyrimidines with a novel carbamoyl substitution, viz. 6‐methyl‐5‐(N‐methylcarbamoyl)‐4‐phenyl‐1,2,3,4‐tetrahydropyrimidine‐2‐thione monohydrate, C13H15N3OS·H2O, (I), and 4‐(4‐chlorophenyl)‐6‐methyl‐5‐(N‐methylcarbamoyl)‐1,2,3,4‐tetrahydropyrimidine‐2‐thione monohydrate, C13H14ClN3OS·H2O, (II), exhibit the structural features of 1,4‐dihydropyridine calcium channel blockers. In both structures, the pyrimidine ring adopts a flattened boat conformation and the carbamoyl side chain is in an extended conformation with an anticlinal orientation. The phenyl ring occupies a pseudo‐axial position with respect to the pyrimidine ring in these structures. Both compounds crystallize with one molecule of water, which participates in a two‐dimensional hydrogen‐bonding network. The molecules are linked into dimers by N—H·S hydrogen bonds in both structures. 相似文献
8.
Andrew Hempel Norman Camerman Zbigniew Dauter Donald Mastropaolo Arthur Camerman 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):455-456
The crystal structure of the title compound, C19H26NO+·Cl? (common name: N,N‐diethyl‐2‐[(4‐phenylmethyl)phenoxy]‐ethanamine hydrochloride), contains one molecule in the asymmetric unit. The planes through the two phenyl rings are roughly perpendicular. Protonation occurs at the N atom, to which the Cl? ion is linked via an N—H?Cl hydrogen bond. The molecule adopts an eclipsed rather than extended conformation. 相似文献
9.
Jarno Kansikas Kaija Sipil 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1383-1385
In the synthesis of 1‐phenyl‐2‐phenylthio‐2‐(tetrahydropyran‐2‐ylthio)ethanol, C19H22O2S2, four diastereoisomers are formed. Two non‐centrosymmetric enantiomeric forms which crystallize in space groups P212121 and Pna21 are presented. The former has an intramolecular hydrogen bond between the hydroxyl group and the O atom of the tetrahydropyran ring. In the latter isomer, the hydroxyl group forms an intermolecular hydrogen bond to the O atom of the tetrahydropyranyl group of a neighbouring molecule, joining the molecules into chains in the c‐axis direction; the O?O distances are 2.962 (4) and 2.764 (3) Å, respectively. The tetrahydropyran rings are in chair conformations in both isomers and the S side chain has an equatorial orientation in the former, but an axial orientation in the latter molecule. 相似文献
10.
C. Ignacio Sainz‐Diaz Ignacio Manzanares Andres Francesch Juanma Garcia‐Ruiz 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o197-o198
Single crystals of the title compound, C39H43N3O11S·2C3H8O, have been obtained from 2‐propanol/water solutions. ET‐743 belongs to the group of ecteinascidins (ETs), which is a family of novel marine tetrahydroisoquinoline derivatives characterized by a monobridged pentacyclic skeleton. Three large principal planar groups are observed in the three‐dimensional structure of the ET‐743 molecule, corresponding to three aromatic units which are nearly perpendicular to each other. In the crystal, the methoxy group on the large fused ring system adopts an anti conformation with respect to the S atom, thus presenting the same conformation as that found in solution. 相似文献
11.
A. Subbiah Pandi D. Velmurugan S. Shanmuga Sundara Raj Hoong‐Kun Fun V. Raghukumar V. T. Ramakrishnan 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(6):723-725
In the title compounds, C17H15N3 and C20H22N4, the methyl derivative crystallizes with two molecules in the asymmetric unit, while the N,N‐diethylamino derivative crystallizes with one molecule per asymmetric unit. The biphenyl twist angle for both molecular structures is approximately 45°. The molecular packing is stabilized by N—H?N hydrogen bonds. 相似文献
12.
A. Bagaria S. Ramakumar M. Gupta V. S. Chauhan 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):o174-o176
The title compound (systematic name: 3‐benzylidene‐6‐isobutylpiperazine‐2,5‐dione), C15H18N2O2, an α,β‐dehydrophenylalanine containing diketopiperazine, crystallizes in the space group P1 with two molecules in the asymmetric unit arranged antiparallel to one another. The α,β‐dehydrophenylalanine (ΔPhe) residue in this cyclic peptide retains its planarity but deviates from the standard conformations observed in its linear analogues. Each type of molecule forms a linear chain with molecules of the same type via pairwise N—H⋯O hydrogen bonds, while weaker C—H⋯O interactions link the chains together to form a three‐dimensional network. 相似文献
13.
Abdelhalim Guelzim Emmanuelle Belloli Said Yous Claude Vaccher 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):100-101
The title compound, C17H23NO2, a tetrahydronaphthalenic analogue of melatonin, crystallizes in the monoclinic space group P21 with one molecule in the asymmetric unit. The crystal structure has been determined by X-ray analysis at room temperature. The absolute configuration of this compound was determined unambiguously as R at the chiral naphthalene C-1 position. 相似文献
14.
Anthony Linden Miyase G. Gündüz Rahime imek Cihat afak 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o227-o230
A mixture of the RR/SS and RS/SR diastereoisomeric pairs of methyl 4‐(2,4‐dichlorophenyl)‐2,7‐dimethyl‐5‐oxo‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxylate, C19H19Cl2NO3, forms cocrystals in which there is one unique molecule in the asymmetric unit, but the molecule displays disorder in the region of the 7‐position of the quinoline ring system as a result of the random occurrence of the diastereoisomers at the same crystallographic site. A similar arrangement exists in the monohydrate cocrystals that form from a mixture of the RR/SS and RS/SR diastereoisomeric pairs of methyl 4‐(2,4‐dichlorophenyl)‐2‐methyl‐7‐phenyl‐5‐oxo‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxylate monohydrate, C24H21Cl2NO3·H2O. These compounds belong to a class of 1,4‐dihydropyridines whose members have calcium modulatory properties. The 1,4‐dihydropyridine rings have the usual shallow boat conformation. In each structure, the 2,4‐dichlorophenyl ring is oriented such that the 2‐chloro substituent is in a synperiplanar orientation with respect to the 1,4‐dihydropyridine ring plane. In each crystal structure, the molecules are linked into chains by N—H⋯O hydrogen‐bonding interactions. 相似文献
15.
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
16.
Carsten Puke Kai Schmengler Kristin Kirschbaum Olaf Conrad Dean M. Giolando 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e542-e542
In the title compound, tetrakis(tetrahydrofuran)lithium(I) tri‐μ‐phenylthiolato‐bis[tris(phenylthiolato)titanate(IV)], [Li(C4H8O)4][Ti2(C6H5S)9], (I), the central structural motif of the [Ti2(SC6H5)9]? anion features a face‐sharing bi‐octahedron. The charge is balanced with a [Li(C4H8O)4]+ cation. The asymmetric unit contains Ti, Li and a heavily disordered tetrahydrofuran molecule on a threefold axis, and two terminal and a bridging thiophenolate moiety and a slightly disordered tetrahydrofuran molecule on general positions. 相似文献
17.
K. SethuSankar S. Saravanan D. Velmurugan Masood Parvez 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):o156-o158
The title compound, 4′‐methoxy‐α,2,3′,4‐tetranitrostilbene, C15H10N4O9, crystallizes in the centrosymmetric space group P21/c with one molecule in the asymmetric unit. The phenyl rings are inclined to one another and form a dihedral angle of 57.4 (1)°. The size of this angle is a result of intermolecular C—H⃛O interactions involving the phenyl H atoms. The torsion angle between the phenyl rings, −7.5 (3)°, indicates a cis geometry between them. The methoxy group is almost coplanar with the phenyl ring, and the nitro groups are twisted with respect to the phenyl rings because of the short H⃛O contacts. The crystal packing is stabilized by C—H⃛O hydrogen bonds, and the intermolecular hydrogen bonds form a C(12) graph‐set chain running along the [010] direction. 相似文献
18.
Dale C. Swenson Vasu Nair Sanjib Bera 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e600-e601
We have synthesized a dideoxydidehydronucleoside derivative, 2(S)‐acetoxymethyl‐4‐[4‐amino‐2‐oxopyrimidin‐1(2H)‐yl]‐2,5‐dihydrofuran, C11H13N3O4, which is an analogue of the potently anti‐HIV active compound, dideoxy‐didehydrocytidine (d4C). The target compound crystallizes with two molecules in the asymmetric unit that differ primarily in the orientation of the C6′‐acetyl group. One molecule has an extended conformation and the orientation of the acetyl group in the second molecule gives an unusual hooked‐shaped conformation. The two conformers form A–B dimers via N—H?N hydrogen bonds. The dimers link via N—H?O hydrogen bonds to form chains parallel to the b cell axis. 相似文献
19.
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
20.
The title azo dye, 2‐(2‐methoxyethoxy)ethyl 4‐[(5‐cyano‐1‐ethyl‐4‐methyl‐2,6‐dioxo‐1,2,3,6‐tetrahydropyridin‐3‐ylidene)hydrazino]benzoate, C21H24N4O6, with a 1‐ethyl‐5‐cyano‐2‐hydroxy‐4‐methyl‐6‐pyridone component, crystallizes in the hydrazone form. Hydrogen bonding mediates the formation of four‐molecule aggregates, which are further grouped into an extended structure by π–π stacking interactions between the aromatic rings of adjacent molecules, with a centroid–centroid separation of 3.697 (2) Å. 相似文献