共查询到20条相似文献,搜索用时 15 毫秒
1.
Michael I. Bruce Nicholas J. Head Brian W. Skelton Allan H. White 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o60-o61
The principal determinants of packing in crystals of the title compound, C12H10O2, which has crystallographically imposed inversion symmetry, are interactions between the alkyne H atoms and the methoxy O atoms [H⋯O = 2.39 (1) Å]. 相似文献
2.
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
3.
Dewey H. Barich Mark T. Zell Douglas R. Powell Eric J. Munson 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o261-o262
The title compounds (both C9H10O4) have nearly planar structures, and the methyl and/or carboxylic acid groups lie out of the molecular plane, as dictated by steric interactions. 2,5‐Dimethoxybenzoic acid (2,5‐DMBA) forms an unusual intramolecular hydrogen bond between the carboxylic acid group and the O atom of the methoxy group in the 2‐position [O⋯O = 2.547 (2) Å and O—H⋯O = 154 (3)°]. 2,4‐DMBA forms a typical hydrogen‐bond dimer with a neighboring molecule. 相似文献
4.
5.
Chun‐Hua Diao Zhi Fan Xin Chen 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):o717-o719
In the title compound, C21H18ClN3O5S·C2H4O2, a combination of O—H...O, N—H...O, C—H...O and C—H...N hydrogen bonds links the components into a complex network containing alternating R44(42), R55(33) and R66(40) rings. 相似文献
6.
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
7.
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
8.
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
9.
Wen‐Xian Chen Qiu‐Ping Liu Gui‐Lin Zhuang Sheng‐Jun Zhou 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(1):5-7
In the title metal–organic framework (MOF), [La(C8H8N2O6)(C2O4)0.5(H2O)]n, the LaIII cation is coordinated by eight O atoms in a square antiprismatic configuration. Each LaIII cation is connected to adjacent LaIII cations by bridging 2,5‐dioxopiperazine‐1,4‐diacetate (PODC2−) and oxalate (lying about an inversion centre) ligands, generating two‐dimensional grid layers. The layers are further linked via the carboxylate groups of the PODC2− ligands in syn–syn and syn–anti modes, resulting in a three‐dimensional framework with a short Schläfli vertex notation of {47.63}{47.67.8}. 相似文献
10.
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
11.
James L. Wardell John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):862-864
In the title compound, C20H16Cl2O4S2, the molecules lie across centres of inversion. A single type of intermolecular C—H?O hydrogen bond, with a C?O distance of 3.254 (3) Å and a C—H?O angle of 132°, links the molecules into ladders whose uprights form C(6) chains and whose rungs enclose centrosymmetric R(22) rings. 相似文献
12.
H. Fu H. Yun T. K. Kwei Y. Okamoto S. Blumstengel A. Walser R. Dorsinville 《先进技术聚合物》1999,10(5):259-264
Poly(2‐benzoyl‐1,4‐phenylene) (PBP) and poly(2,5‐dibenzoyl‐1,4‐phenylene) (PDBP) were synthesized by coupling polymerization using a Ni catalyst of 2,5‐dichlorobenzophenone and 2,5‐dichloro‐1,4‐dibenzophenone, respectively. These polymers are soluble in common organic solvents, have high thermal stability and show bright blue photoluminescence. Light‐emitting diodes fabricated with these polymers as the active layer emit blue electroluminescence with wavelength at 433 nm for PBP and 475 nm for PDBP. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
13.
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
14.
Manuela Müller Hans‐Wolfram Lerner Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(8):796-800
2,5‐[(Diphenylphosphanyl)methyl]‐1,1,2,4,4,5‐hexaphenyl‐1,4‐diphospha‐2,5‐diboracyclohexane shows polymorphism as two tetrahydrofuran (THF) disolvates [C64H58B2P4·2C4H8O, (Ia) and (Ib)] and pseudo‐polymorphism as its toluene monosolvate [C64H58B2P4·C7H8, (Ic)]. In each of polymorphs (Ia) and (Ib), the diphosphadiboracyclohexane molecule is located on a centre of inversion. The THF molecule of (Ib) is disordered over two sites, with a site‐occupation factor of 0.612 (8) for the major‐occupied site. Both structures crystallize in the same space group (P21/n), but they display a different crystal packing. For pseudo‐polymorph (Ic), although the space group is P21/c, which is just a different setting of the P21/n space group of (Ia) and (Ib), the crystal packing is completely different. Although the crystal packing in these three structures is significantly different, their molecular conformations are surprisingly the same. 相似文献
15.
Yi‐Zhi Li Wei‐Wei Liu Yan‐Jie Li Guo‐Jun Pan Hong‐Wen Hu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):o611-o612
An N,N′‐disubstituted dithiooxamide derivative reacts with 1,2‐dibromoethane to produce the title compound, C18H18N2S2, a heterocycle with a double Schiff base. In the crystal structure, the molecule of the title compound lies on a twofold axis. Weak C—H⋯π interactions are the principal intermolecular forces, mediating the formation of layers parallel to the ab plane. Each molecule participates as donor and acceptor in two such contacts. 相似文献
16.
Joo Figueira Joo Rodrigues Luca Russo Kari Rissanen 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(2):o33-o36
2,5‐Diethoxy‐1,4‐bis[(trimethylsilyl)ethynyl]benzene, C20H30O2Si2, (I), constitutes one of the first structurally characterized examples of a family of compounds, viz. the 2,5‐dialkoxy‐1,4‐bis[(trimethylsilyl)ethynyl]benzene derivatives, used in the preparation of oligo(phenyleneethynylene)s via Pd/Cu‐catalysed cross‐coupling. 2,5‐Diethoxy‐1,4‐diethynylbenzene, C14H14O2, (II), results from protodesilylation of (I). 1,4‐Diethynyl‐2,5‐bis(heptyloxy)benzene, C24H34O2, (III), is a long alkyloxy chain analogue of (II). The molecules of compounds (I)–(III) are located on sites with crystallographic inversion symmetry. The large substituents either in the alkynyl group or in the benzene ring have a marked effect on the packing and intermolecular interactions of adjacent molecules. All the compounds exhibit weak intermolecular interactions that are only slightly shorter than the sum of the van der Waals radii of the interacting atoms. Compound (I) displays C—H...π interactions between the methylene H atoms and the acetylenic C atom. Compound (II) shows π–π interactions between the acetylenic C atoms, complemented by C—H...π interactions between the methyl H atoms and the acetylenic C atoms. Unlike (I) or (II), compound (III) has weak nonclassical hydrogen‐bond‐type interactions between the acetylenic H atoms and the ether O atoms. 相似文献
17.
Hideyuki Higashimura Kiyoshi Fujisawa Yoshihiko Moro‐oka Shuhei Namekawa Masaaki Kubota Akinobu Shiga Hiroshi Uyama Shiro Kobayashi 《Macromolecular rapid communications》2000,21(16):1121-1124
New heat‐reversibly crystalline poly‐(alkylated phenylene oxide)s are described. the oxidative polymerization of 2,5‐dimethylphenol catalyzed by (1,4,7‐triisopropyl‐1,4,7‐triazacyclononane) copper dichloride produced poly(2,5‐dimethyl‐1,4‐phenylene oxide), which showed heat‐reversible crystallinity with a high melting point at ca. 300°C, although the isomeric polymer, poly(2,6‐dimethyl‐1,4‐phenylene oxide), never recrystallizes once melted. The polymerization of 2,5‐diethylphenol and 2,5‐dipropylphenol gave the polymers consisting of 1,4‐phenylene oxide units; the latter polymer possessed heat‐reversible crystallinity, however, the former one did not. 相似文献
18.
Hyun Hoon Song Tai‐Yon Cho D. P. Heberer T. D. Dang F. E. Arnold Loon‐Seng Tan 《Journal of Polymer Science.Polymer Physics》2001,39(5):559-565
Crystal‐packing, optical, and electrical properties of poly(2,5‐dihydroxy‐1,4‐phenylene benzobisthiazole) (DiOH‐PBZT) and copolymers of DiOH‐PBZT/poly(1,4‐phenylene‐benzobisthiazole) (PBZT) were examined. Intramolecular hydrogen bonds between the hydroxyl units and the neighboring nitrogen atoms, as evidenced by the IR spectra, led to the formation of a pseudoladder chain structure and changed the chain packing. The (200) and (010) planes were both affected by the copolymer composition, with the (200) plane spacing increasing from 5.895 to 6.482 Å and the (010) plane spacing decreasing from 3.539 to 3.404 Å with the transition from the unsubstituted PBZT homopolymer to the DiOH‐PBZT homopolymer. The cell dimensions of the copolymers were simple averages of those of the individual homopolymers, suggesting the isomorphic crystal structure formation of the two units. The c‐axis spacing, however, remained unchanged. The increase in the conjugation length of the copolymers as the dihydroxy content increased was confirmed by the bathochromic shift of the absorption band in the ultraviolet–visible spectra. The intrinsic conductivities of the copolymers were 3 orders of magnitude higher than that of the unsubstituted PBZT. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 559–565, 2001 相似文献
19.
Andrzej Gzella Maria D. Rozwadowska 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):981-982
The absolute configuration of the title compound, alternatively called (+)‐(4,5‐dihydro‐2,5‐diphenyloxazol‐4‐yl)methanol, C16H15NO2, has been confirmed as 4S,5S. The hydroxymethyl group and phenyl ring at the asymmetric C atoms exhibit β and α orientations, respectively. The exocyclic C—C bonds at the asymmetric C atoms are mutually anticlinal (?ac). The hydroxyl group and the N atom of the oxazoline ring are involved in an intermolecular hydrogen bond leading to chains of molecules. 相似文献
20.
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