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1.
9,10‐Diphenyl‐9,10‐epidioxyanthracene and 9,10‐dihydro‐10,10‐dimethoxy‐9‐phenylanthracen‐9‐ol
Anwar Usman Hoong‐Kun Fun Yun Li Jian‐Hua Xu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o308-o310
9,10‐Diphenyl‐9,10‐epidioxyanthracene, C26H18O2, (I), was accidentally used in a photooxygenation reaction that produced 9,10‐dihydro‐10,10‐dimethoxy‐9‐phenylanthracen‐9‐ol, C22H20O3, (II). In both compounds, the phenyl rings are approximately orthogonal to the anthracene moiety. The conformation of the anthracene moiety differs as a result of substitution. Intramolecular C—H⃛O interactions in (I) form two approximately planar S(5) rings in each of the two crystallographically independent molecules. The packing of (I) and (II) consists of molecular dimers stabilized by C—H⃛O interactions and of molecular chains stabilized by O—H⃛O interactions, respectively. 相似文献
2.
Eric Cuthbertson Christopher S. Frampton David D. MacNicol 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):431-432
The structures of the highly substituted title heterocycles, C20H22N2S and C20H22N2O2S, have been determined at 123 (1) K. Both molecules possess exact C2 symmetry and the seven‐membered rings have very similar twist‐boat conformations. The magnitudes of the C—S—C bond angles, 107.13 (6) and 108.27 (7)°, respectively, are influenced significantly by the four substituent methyl groups on the seven‐membered rings. 相似文献
3.
Bernardo Masci Martine Nierlich Pierre Thury 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o86-o87
2,3,6,7‐Tetrahydroxy‐9,10‐dimethyl‐9,10‐dihydro‐9,10‐ethanoanthracene crystallizes with 1,4‐dioxane to give a bis‐solvate, C18H18O4·2C4H8O2. The bis(catechol) molecule is located on a twofold axis and the two aromatic rings form a dihedral angle of 130.61 (4)°. Hydrogen bonds are formed between the hydroxyl groups and either a neighbouring bis(catechol) molecule or the ether‐O atom of a dioxane molecule. 相似文献
4.
John Reglinski Michelle K. Taylor Alan R. Kennedy 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o169-o172
We have isolated and crystallographically characterized the three homologous compounds N,N′‐bis(2‐methoxybenzylidene)ethane‐1,2‐diamine (MeSalen), C18H20N2O2, N,N′‐bis(2‐methoxybenzylidene)propane‐1,3‐diamine (MeSalpr), C19H22N2O2, and N,N′‐bis(2‐methoxybenzylidene)butane‐1,4‐diamine (MeSalbu), C20H24N2O2. In contrast with MeSalpr, the molecules of MeSalen and MeSalbu, which have an even number of methylene units, have crystallographic symmetry. Comparing these methoxy‐substituted species with their hydroxy equivalents shows that the aryl rings rotate upon removal of the O—H⋯N hydrogen bonds. The packing of MeSalen and MeSalpr is controlled by C—H⋯π interactions, whereas that of MeSalbu has only van der Waals contacts. 相似文献
5.
Guo‐Wu Rao Wei‐Xiao Hu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o281-o282
The title compound, C22H24N4O4, was prepared from propyl chloroformate and 3,6‐diphenyl‐1,2‐dihydro‐s‐tetrazine. This reaction yields the title compound rather than dipropyl 3,6‐diphenyl‐1,4‐dihydro‐s‐tetrazine‐1,4‐dicarboxylate. The 2,3‐diazabutadiene group in the central six‐membered ring is not planar; the C=N double‐bond length is 1.285 (2) Å, and the average N—N single‐bond length is 1.401 (3) Å, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie 0.3268 (17) Å from the plane of the ring. The molecule has twofold crystallographic symmetry. 相似文献
6.
Gakuse Hoshina Masanobu Tsuchimoto Shigeru Ohba 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e122-e122
In crystals of the title compound, [Ni(C28H22N2O2)], the coordination geometry around the Ni atom is square planar with a slight tetrahedral distortion. The five‐membered N,N′‐chelate ring adopts a distorted gauche conformation with the two phenyl groups in axial and equatorial orientations. 相似文献
7.
Uwe‐Christoph Knig Michael Berkei Claudia Hirsch Hans Preut Terence Nigel Mitchell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e450-e451
The synthesis and the X‐ray structural analysis of the title compound, μ‐chloro‐1:2κ2Cl‐trichloro‐1κCl,2κ2Cl‐tetramethyl‐1κ2C,2κ2C‐(N‐methylpyrrolidin‐2‐one)‐1κO‐ditin(IV), [Sn2Cl4(CH3)4(C5H9NO)], are described. The title compound is found to exhibit a distorted trigonal–bipyramidal geometry at both SnIV atoms. The Sn—Cl—Sn angle involving the bridging chlorine ligand is 135.56 (5)°, with the Sn—Cl bond lengths being 2.5704 (13) and 3.1159 (13) Å. 相似文献
8.
Zhi‐Min Jin Li Li Mei‐Chao Li Mao‐Lin Hu Liang Shen 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o642-o643
The title compound, C14H24N2O4, consists of two symmetric moieties related through a twofold axis. The whole molecule has a cis conformation. Both the ionic enol form and the non‐ionic keto form make comparable contributions to the structure. In the crystal structure, infinite supramolecular chains are formed through N—H⋯O hydrogen bonds. 相似文献
9.
Viktor A. Tafeenko Aleksander N. Nikolaev Rene Peschar Olga V. Kaukova Henk Schenk Leonid A. Aslanov 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o297-o299
The crystal structure of the title compound, C6H8N+·C8HN4O2−, is characterized by three independent ion pairs (A, B and C) in the asymmetric unit. Each ion pair consists of an anion and a cation, and the three ion pairs have similar geometric parameters. All the anions are arranged as dianion dimers via two N—H⋯O hydrogen bonds and the dimers form one‐dimensional columns parallel to the b axis as a result of π–π interactions. The cations are also stacked, in two different ways: one type of stacking consists of alternating A and B cations, while the other type consists of C cations only. Each dianion dimer stack is surrounded by eight stacks of cations and is not connected directly to other dianion stacks. 相似文献
10.
Masood Parvez Kaleem M. Khosa Muhammad Mazhar Saqib Ali Manzar Sohail 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(1):m51-m54
The crystal structures of 3,3‐dimethyl‐3‐(trichlorogermyl)propionic acid, [Ge(C5H9O2)Cl3], 3,3‐dimethyl‐3‐(triphenylgermyl)propionic acid, [Ge(C6H5)3(C5H9O2)], and 3,3‐dimethyl‐3‐(tri‐p‐tolylgermyl)propionic acid, [Ge(C7H7)3(C5H9O2)], have slightly distorted tetrahedral geometries about the Ge atoms. All the structures form dimers via strong O—H·O hydrogen bonds, resulting in eight‐membered rings that can be best described in terms of graph‐set notation (8). 相似文献
11.
Hiroyuki Hosomi Shigeru Ohba Yoshikatsu Ito 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):e260-e261
In the title two adducts, C3H12N22+·2C9H6NO4?, (I), and C6H16N22+·2C9H6NO4?, (II), hydrogen bonds between the diammonium and carboxylate ions form a two‐dimensional network parallel to the ab plane in (I) and one‐dimensional chains along the c axis in (II). The cyclohexanediammonium ion in (II) has a crystallographic twofold axis. 相似文献
12.
Anthony Linden Fatemeh Ghorbani‐Salman Pour Roland A. Breitenmoser Heinz Heimgartner 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):634-637
The morpholine ring of the title dione, C13H15NO3, shows a boat conformation that is distorted towards a twist‐boat, with the boat ends being the two Csp3 atoms of the ring. The benzyl substituent is in the favoured `exo' position. In the monothione derivative, (±)‐6‐benzyl‐3,3‐dimethyl‐5‐thioxomorpholin‐2‐one, C13H15NO2S, this ring has a much flatter conformation that is midway between a boat and an envelope, with the dimethyl end being almost planar. The orientation of the benzyl group is `endo'. The dithione derivative, (±)‐6‐benzyl‐3,3‐dimethylmorpholine‐2,5‐dithione, C13H15NOS2, has two symmetry‐independent molecules, which show different puckering of the morpholine ring. One molecule has a flattened envelope conformation distorted towards a screw‐boat, while the conformation in the other molecule is similar to that in the monothione derivative. Intermolecular hydrogen bonds link the molecules in the three compounds, respectively, into centrosymmetric dimers, infinite chains, and dimers made up of one of each of the symmetry‐independent molecules. 相似文献
13.
Guangrong Zheng Sean Parkin Linda P. Dwoskin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o9-o11
The crystal structures of the title compounds, 2α,4α‐dibenzyl‐3α‐tropanol (2α,4α‐dibenzyl‐8‐methyl‐8‐azabicyclo[3.2.1]octan‐3α‐ol), C22H27NO, (I), and 2α,4α‐dibenzyl‐3β‐tropanol (2α,4α‐dibenzyl‐8‐methyl‐8‐azabicyclo[3.2.1]octan‐3β‐ol), C22H27NO, (II), show that both compounds have a piperidine ring in a chair conformation and a pyrrolidine ring in an envelope conformation. Isomer (I) is asymmetric, the benzyl groups having different orientations, whereas isomer (II) is mirror symmetric, and the N and O atoms, the C atom attached to the hydroxy group, and the methyl C atom attached to the N atom lie on the mirror plane. In the crystal structures of both (I) and (II), the molecules are linked together by intermolecular O—H⋯N hydrogen bonds to form chains that run parallel to the a direction in (I) and parallel to b in (II). 相似文献
14.
Gang Xue Qi Fang Wentao Yu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):o653-o655
4,5‐Propylenedithio‐1,3‐dithiole‐2‐thione, C6H6S5, (I), crystallizes in the centrosymmetric space group P21/c. The molecular packing is characterized by pairs of S⋯S intermolecular contacts between neighbouring molecules, which may account for the rather high thermal stablity of the crystal. 4,5‐Propylenedithio‐1,3‐dithiol‐2‐one, C6H6OS4, (II), in which an O atom replaces the terminal S atom of (I), crystallizes in the non‐centrosymmetric polar space group Cc. The packing pattern of (II) indicates that the macropolarization direction is along [101]. Although the packing patterns are qualitatively significantly different, the molecular structures of (I) and (II) are similar, each exhibiting a chair conformation. 相似文献
15.
Gregori A. Caignan Elizabeth M. Holt 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):934-935
The title compound, C21H27NO6, has been crystallized from ethanol containing nitrobenzene and shows the phenyl ring, B, in an ap conformation. This structure may be compared with that of the molecule crystallized from ethanol alone, in which the B ring is seen in an sp conformation. The isolation of this rotamer has implications for the understanding of the docking of calcium beta‐blocking dihydropyridine molecules with their receptor site. 相似文献
16.
Ahmed El‐Shafei David Hinks Paul D. Boyle Harold S. Freeman 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):o569-o571
The title compounds, C18H22Cl2N2O2 and C20H28N2O2, respectively, are isomorphous. The molecules lie at general positions in the unit cell. In each structure, chemically equivalent but crystallographically inequivalent amine N atoms exhibit different degrees of pyramidalization. The structures exhibit weak N—H⋯N hydrogen bonding, which is influenced by the differences in hybridization around the amine N atoms. The torsion angles across the biphenyl linkage for the two compounds are 67.2 (2) and 68.3 (3)°. 相似文献
17.
Roger D. Willett Salim F. Haddad Brendan Twamley 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e437-e437
The title compound, (C5H6Br2N3)2[CuBr4], contains isolated substituted pyridinium cations and [CuBr4]2? anions. The diaminodibromopyridinium ions are planar, while the CuII ions have a distorted compressed tetrahedral coordination with C2 symmetry. The two independent trans‐Br—Cu—Br angles are 128.9 (1) and 136.0 (1)°, with Cu—Br distances of 2.3939 (15) and 2.3790 (16) Å. 相似文献
18.
Russell G. Baughman Kenneth L. Martin Rajendra K. Singh James O. Stoffer 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o103-o106
In 2,4‐dihydroxybenzaldehyde 2,4‐dinitrophenylhydrazone N,N‐dimethylformamide solvate {or 4‐[(2,4‐dinitrophenyl)hydrazonomethyl]benzene‐1,3‐diol N,N‐dimethylformamide solvate}, C13H10N4O6·C3H7NO, (X), 2,4‐dihydroxyacetophenone 2,4‐dinitrophenylhydrazone N,N‐dimethylformamide solvate (or 4‐{1‐[(2,4‐dinitrophenyl)hydrazono]ethyl}benzene‐1,3‐diol N,N‐dimethylformamide solvate), C14H12N4O6·C3H7NO, (XI), and 2,4‐dihydroxybenzophenone 2,4‐dinitrophenylhydrazone N,N‐dimethylacetamide solvate (or 4‐{[(2,4‐dinitrophenyl)hydrazono]phenylmethyl}benzene‐1,3‐diol N,N‐dimethylacetamide solvate), C19H14N4O6·C4H9NO, (XII), the molecules all lack a center of symmetry, crystallize in centrosymmetric space groups and have been observed to exhibit non‐linear optical activity. In each case, the hydrazone skeleton is fairly planar, facilitated by the presence of two intramolecular hydrogen bonds and some partial N—N double‐bond character. Each molecule is hydrogen bonded to one solvent molecule. 相似文献
19.
Anthony Linden Markus Furegati Andreas J. Rippert 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o223-o225
The title compounds, C20H24O7 and C40H32O, respectively, are racemic oxepines, the molecules of which contain a chiral axis. Both molecules possess crystallographic C2 symmetry and the seven‐membered ring adopts a twisted‐boat conformation. 相似文献
20.
Robert W. Clark Ilia A. Guzei Sergei A. Ivanov Steven D. Burke William T. Lambert 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):844-845
The results of a single‐crystal X‐ray experiment and density functional theory calculations performed for the title compound, C20H22O4, demonstrate that the lowest energy conformation of this molecule does not contain C2 molecular symmetry. 相似文献