共查询到20条相似文献,搜索用时 38 毫秒
1.
Grard Ppe Patrick Hannesschlager Pierre Brun 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):e251-e252
The title compound, [Cr(C15H14O)(CO)3], is a chromene complexed with tricarbonylchromium and it exhibits photochromic properties. The molecular geometry is compared to that of two similar complexes. The analysis results indicate that complexation has minor effects on the chromene structure. 相似文献
2.
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
3.
Jing‐Kun Xu Shou‐Zhi Pu Tian‐She Yang Ru‐Ji Wang 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(9):o568-o570
The title compound, C23H22F6O4S2, a photochromic dithienylethene, is a promising material for optical storage and other optoelectrical devices. The molecule adopts a photoactive antiparallel conformation in the crystalline state. The distance between the two reactive C atoms which are involved in potential ring closure is 3.829 (4) Å. The dihedral angles between the central cyclopentene ring and the adjacent thiophene rings are 55.38 (7) and 54.81 (9)°. The colourless crystals turn magenta when exposed to UV radiation and the process is reversible. 相似文献
4.
Sara K. Metcalf Elizabeth M. Holt 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1228-1231
Diethyl 4‐(2,5‐dimethoxyphenyl)‐2,6‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C21H27NO6, (I), diethyl 4‐(3,4‐dimethoxyphenyl)‐2,6‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C21H27NO6, (II), and diethyl 2,6‐dimethyl‐4‐(3,4,5‐trimethoxyphenyl)‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C22H29NO7, (III), crystallize with hydrogen‐bonding networks involving the H atom bonded to the N atom of the 1,4‐dihydropyridine ring and carbonyl O atoms in (I) and (II). Unusually, (III) shows O atoms of methoxy groups serving as hydrogen‐bond acceptors. 相似文献
5.
Shou‐Zhi Pu Fu‐Shi Zhang Ru‐Ji Wang Qiang Liang 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):o305-o307
The title compound, C17H14F6O2S2, a photochromic diarylethene, is one of the most promising materials for optical memories and other optoelectronic devices. The hexafluorocyclopentene group and the two thiophene rings are all planar, and the dihedral angles between the cyclopentene ring and the adjacent thiophene rings are 46.4 (1) and 49.5 (1)°. 相似文献
6.
Shou‐Zhi Pu Gang Liu Bing Chen Ru‐Ji Wang 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(10):o599-o601
The title compound, C27H18F6S2, a novel photochromic hybrid diarylethene derivative containing 2‐ and 3‐thienyl substituents, is one of the most promising photochromic candidates with shorter wavelength for optical storage and other optoelectronic devices. In the crystal structure, the molecule adopts a photoactive antiparallel conformation. The distance between the two reactive C atoms, i.e. the ring C atoms to which the methyl groups are attached, is 3.430 (4) Å. The dihedral angles between the thienyl and adjacent phenyl rings are 26.8 (2) and 33.98 (9)°. 相似文献
7.
David J. Wiedenfeld Vladimir N. Nesterov Mark A. Minton Crystal L. Montoya 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o536-o538
The title compounds, 1‐chloro‐3,6‐dimethoxy‐2,5‐dimethylbenzene, (IIIa), and 1‐chloro‐3,6‐dimethoxy‐2,4‐dimethylbenzene, (IIIb), both C10H13ClO2, were obtained from 2,5‐ and 2,6‐dimethyl‐1,4‐benzoquinone, respectively, and are intermediates in the synthesis of ammonium quinone derivatives. The isomers have different substituents around the methoxy groups and crystallize in different space groups. In both molecules, the methoxy groups each have different orientations with respect to the benzene ring. In both cases, one methoxy group lies in the plane of the ring and can participate in conjugation with the aromatic system, while the second is almost perpendicular to the plane of the aromatic ring. The C—O—C bond angles around these substituents are also different: 117.5 (4) and 118.2 (3)° in (IIIa) and (IIIb), respectively, when the methoxy groups lie in the plane of the ring, and 114.7 (3) and 113.6 (3)° in (IIIa) and (IIIb), respectively, when they are out of the plane of the ring. 相似文献
8.
P. Perez‐Lourido J. A. García‐Vzquez J. Romero P. Fernandez A. Sousa‐Pedrares A. Sousa 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):e101-e102
The title compound, [2‐Ph2P(O)C6H4S]2 or C36H28O2P2S2, obtained by electrochemical oxidation of 2‐(diphenylphosphino)benzenethiol, has twofold crystallographic symmetry. Principal dimensions include S—S 2.0212 (15) Å, S—C 1.786 (3) Å and C—S—S—C 81.34 (14)°. 相似文献
9.
Amitabh Jha Sanjay Malhotra Virinder S. Parmar William Errington 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):899-900
The title compound, 2,2‐dimethylchroman‐6‐ol, C11H14O2, has been identified as a side product from the condensation of hydroquinone with 2‐methylbut‐3‐en‐2‐ol. The pyran ring has a half‐chair conformation. The hydroxyl groups are involved in intermolecular hydrogen bonding which generates infinite spiral chains around the fourfold screw axes; the O?O hydrogen‐bonded distances are 2.661 (1) Å. 相似文献
10.
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
11.
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
12.
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
13.
Leah M. Schlientz Karl S. Hagen 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o533-o535
The title compound, C48H60O8·3C3H7NO, is a derivative of calix[4]arene in the cone conformation, modified with distal carboxylic acid functional groups at the lower rim. A clathrate dimethylformamide (DMF) molecule is located within the calix[4]arene cone, and two DMF solvate molecules participate in hydrogen bonding with the carboxylic acid groups. Intramolecular hydrogen bonds are also formed between the OH groups and the adjacent ether groups in the partially substituted calix[4]arene. 相似文献
14.
John Bacsa Desmond Eve Kim R. Dunbar 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(1):m58-m60
Single crystals of the title compound, [Co(C2O4)(H2O)2]n, have been prepared by hydrothermal methods and characterized by X‐ray diffraction analysis. The crystal structure consists of infinite one‐dimensional chains of diaquacobalt(II) units bridged by oxalate groups. These chains lie on twofold symmetry axes parallel to the b axis, and the [Co(C2O4)]n system is nearly planar within experimental error. The cobalt(II) coordination polyhedra are irregular octahedra, with oxalate O atoms at the equatorial positions and water molecules at the axial positions. The chains are linked by hydrogen bonds via the water molecules. 相似文献
15.
S. Ferfra N. Ahabchane E. M. Essassi M. Pierrot 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e463-e464
The crystal structure of the title compound, ethyl 2,2‐dihydroxy‐2‐(3‐oxo‐3,4‐dihydroquinoxalin‐2‐yl)acetate, C12H12N2O5, indicates a short intramolecular contact between the N1 atom and a hydroxyl group [2.772 (4) Å]. Two intermolecular hydrogen bonds participate in the molecular packing. 相似文献
16.
Jem‐Mau Lo Golam Mostafa Ling‐Yin Chang Fen‐Ling Liao Tian‐Huey Lu 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o276-o277
The title compound, C10H18N2S2, acts as an important precursor for the synthesis of the pharmaceutically important diaminedithiol ligand system. The molecule has a local twofold axis and the arrangement of the S2N2 donor atoms in the macrocycle is anticlinal. 相似文献
17.
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
18.
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
19.
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
20.
F. Betül Kaynak Süheyla
zbey Turan
ztürk Erdal Erta 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):926-928
In the title compound, C17H10S5, the dithiine ring adopts a boat conformation while the dithiole ring has an envelope conformation. The phenyl groups are planar and make dihedral angles of 40.7 (2) and 59.8 (2)° with the best plane of the thiine ring. The shortest intermolecular S?S contact is 3.305 (2) Å. 相似文献