共查询到20条相似文献,搜索用时 15 毫秒
1.
Paul D. Robinson Duy H. Hua Jingmei Fan Lanzhu Liu James W. McGill Mohammed Arshid Cal Y. Meyers 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1471-1472
The title compound, C14H20O8, was synthesized from the hydrogenation of tetramethyl 1,4‐cyclohexadiene‐1,2,4,5‐tetracarboxylate with a catalytic amount of palladium/carbon. All four carbonyl moieties of the methyl ester groups are on the same face of the chair‐conformed ring. The substantial ring distortion associated with the 1,3‐diaxial methoxycarbonyl substituents is reflected in the large difference between bond angles as well as torsion angles, respectively, that in undistorted cyclohexanes would be approximately the same. 相似文献
2.
Craig M. Forsyth Douglas R. MacFarlane Pamela M. Dean 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):m169-m170
The title compound, also known as sodium nicotinate, Na+·C6H4NO2−, consists of two unique Na atoms coordinated to two unique pyridine‐3‐carboxylate ligands through the N atoms and carboxylate groups. One Na atom and one pyridine‐3‐carboxylate ligand lie on a twofold axis. Extensive Na coordination results in a three‐dimensional array comprising infinite NaO2CR chains linked by intrachain Na—N bonds. 相似文献
3.
Artur Sikorski Karol Krzymiski Antoni Konitz Jerzy Baejowski 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(1):o50-o52
The title compounds, 2‐ethylphenyl acridine‐9‐carboxylate, C22H17NO2, (I), and 2,5‐dimethylphenyl acridine‐9‐carboxylate, C22H17NO2, (II), form triclinic and monoclinic crystals, respectively. Related by a centre of symmetry, adjacent molecules of (I) are linked in the lattice via a network of C—H·π and non‐specific dispersive interactions. As a result, acridine moieties and independent phenyl moieties of (I) are parallel in the lattice. The molecules of (II), arranged in a `head‐to‐tail' manner and related by a centre of symmetry, form pairs stabilized via C—H·π interactions. These are linked in the crystal via dispersive interactions. Acridine and independent phenyl moieties lie parallel within the pairs, while adjacent pairs are perpendicular, forming a herring‐bone pattern. 相似文献
4.
Akira Uchida Masatoshi Hasegawa Hiroshi Manami 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(8):o435-o438
cis,cis,cis‐1,2,4,5‐Cyclohexanetetracarboxylic acid, C10H12O8, (I), contains a mirror plane and the cyclohexane ring exhibits a chair conformation. Two crystallographically independent hydrogen bonds form (14), (16) and (16) ring motifs, and propagation of these two hydrogen bonds along the c and b axes generates (16) and (7) chains. cis,cis,cis‐1,2:4,5‐Cyclohexanetetracarboxylic dianhydride, C10H8O6, (II), was prepared by the reaction of (I) with acetic anhydride. The cyclohexane ring of (II) exhibits a boat conformation and the dihedral angle between the two anhydro rings is 117.5 (1)°. 相似文献
5.
Keiichi Noguchi Hidekazu Kondo Yasushi Ichikawa Junichiro Washiyama Kenji Okuyama 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):o528-o530
The 20‐membered ring of the title compound, C16H24O8, adopts an approximately flat rectangular structure with three‐ and seven‐bond sides and lies across a crystallographic center of inversion. The corners of the ring occur at both ends of one of the planar ester segments. All of the carbonyl O atoms are involved in intermolecular C—H⋯O hydrogen bonds. 相似文献
6.
Jan W. Bats Andreas Rivas Nass A. Stephen K. Hashmi 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):814-817
The crystal structure of the title compound, (2,2′‐bipyridyl‐κ2N,N′)(tetraallyl 3,3,3′,3′‐tetramethyl‐1,1′‐bicyclopropane‐1,1′,2,2′‐tetracarboxylato‐κ2C2,C2′)palladium(II), [Pd(C26H32O8)(C10H8N2)], is disordered above 194 K. A doubling of the unit cell is observed on cooling. The structure at 143 K contains two ordered molecules related by a pseudo‐translation vector of approximately (0.44,0.00,0.50) or a pseudo‐inversion center at approximately (0.22,0.00,0.25). Weak intermolecular C—H?O interactions are enhanced in the low‐temperature structure. 相似文献
7.
Hiroyuki Hosomi Shigeru Ohba Yoshikatsu Ito 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):e511-e511
In the title adduct, C10H6O8·2C9H9NO, benzene‐1,2,4,5‐tetracarboxylic acid has a crystallographic twofold axis parallel to b and forms a flat zigzag chain along c linked by O— H?O cyclic hydrogen bonds with cinnamamide molecules. 相似文献
8.
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
9.
Hong‐Xia Zhang Shou‐Tian Zheng Guo‐Yu Yang 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):o545-o546
The title compound, tetramethylammonium 4,4′,6,6′‐tetrahydroxy‐2,2′‐spirobi(cyclotriboroxane) 0.25‐hydrate, C4H12N+·B5H4O10−·0.25H2O, was synthesized under mild solvothermal conditions. The B5O6(OH)4− clusters are connected by strong hydrogen‐bonding interactions into a three‐dimensional structure containing rectangular channels along the a axis, in which the C4H12N+ ions and water molecules are located. 相似文献
10.
Feyissa Gadissa Gelalcha Brbel Schulze Peter Lnnecke 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o180-o182
The title compound, C6H12O4, also known as dimeric acetone peroxide, Me2(C2O4)Me2, has crystallographically imposed inversion symmetry and adopts a chair conformation in the solid state. This structure contrasts with that of the sulfur homologue Me2(C2S4)Me2, which has crystallographically imposed symmetry and crystallizes in a twist‐boat conformation. Crystals of the title compound are twinned along the reciprocal c* axis. 相似文献
11.
Mao‐Lin Hu Hong‐Ping Xiao Ji‐Xin Yuan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):m112-m113
In the title compound, poly[[aqua(1,10‐phenanthroline)cobalt(II)]‐μ4‐dihydrogen benzene‐1,2,4,5‐tetracarboxylato], [Co(C10H4O8)(C12H8N2)(H2O)]n, each cobalt(II) cation has an octahedral geometry completed by one aqua O atom, three carboxy O atoms belonging to three H2TCB2− anions (H2TCB2− is dihydrogen benzene‐1,2,4,5‐tetracarboxylate) and two N atoms from a 1,10‐phenanthroline molecule. In the asymmetric unit, there are two half H2TCB2− anions lying about independent inversion centres. The bridging H2TCB2− anions have two coordination modes, viz.μ2‐H2TCB2− and μ4‐H2TCB2−, resulting in a two‐dimensional coordination polymer. Furthermore, a three‐dimensional network is formed by Ocarboxy⋯Ocarboxy hydrogen‐bond interactions, with H⋯A distances in the range 1.69–1.82 Å, and Ocarboxy⋯Owater interactions, with H⋯A distances in the range 1.91–1.94 Å. 相似文献
12.
Ana María Atria Maria Teresa Garland Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(8):m275-m278
The title compound, [Co(C5H7N6)2(H2O)4](C10H2O8)·4H2O, is an ionic structure comprising a [Co(Hdap)2(H2O)4]4+ cation (dap is 2,6‐diaminopurine) in a general position, two benzene‐1,2,4,5‐tetracarboxylate (btc4−) anions straddling two different inversion centres and four solvent water molecules. The structure presents a remarkable degree of pseudosymmetry, with the CoII cation lying almost exactly on a noncrystallographic pseudo‐inversion centre. The overall spatial arrangement can be described in terms of cationic and anionic chains running along the [111] direction and linked into a three‐dimensional network by a very complex hydrogen‐bonding scheme in which all the available N—H and O—H groups take part. 相似文献
13.
Maciej Kubicki Penelope W. Codding 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(6):728-729
The crystal structure of the second monoclinic P21/c form of the β‐carboline‐3‐carboxylate, C13H10N2O2, has been determined. Very small changes in the packing scheme lead to a different unit cell; the role of weak C—H?O hydrogen bonds seems to be crucial. 相似文献
14.
E. Yang Jian Zhang Yi‐Hang Wen Yu‐Biao Chen Yao Kang Zhao‐Ji Li Yuan‐Gen Yao 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):m280-m282
The hydrothermal reaction of an aqueous solution of Cu(CH3COO)2·H2O, 1,2,4,5‐benzenetetracarboxylic acid and 4,4′‐bipyridine gave rise to the interesting title three‐dimensional polymer {[Cu6(btec)3(4,4′‐bpy)3(H2O)2]·2H2O}n (btec is 1,2,4,5‐benzenetetracarboxylate, C10H2O84−, and 4,4′‐bpy is 4,4′‐bipyridine, C10H8N2), in which each btec ligand links six copper(II) cations into a lamellar [Cu6(btec)3(H2O)2]n subpolymer framework. There are two distinct diamine units and two distinct carboxylate units, with one of each lying across an inversion centre. 相似文献
15.
Jian‐Hai Luo Xi‐He Huang Chang‐Cang Huang Xiao‐Juan Chen 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):m273-m276
Two pseudo‐polymorphic polymers, poly[ethylenediammonium [[aquacopper(II)]‐μ4‐benzene‐1,2,4,5‐tetracarboxylato] dihydrate], {(C2H10N2)[Cu(C10H2O8)(H2O)]·2H2O}n, (I), and poly[ethylenediammonium [copper(II)‐μ4‐benzene‐1,2,4,5‐tetracarboxylato] 2.5‐hydrate], {(C2H10N2)[Cu(C10H2O8)]·2.5H2O}n, (II), contain two‐dimensional anionic layers, ethylenediammonium (H2en) cations acting as counter‐ions and free water molecules. Although the topological structures of the two anionic layers are homologous, the coordination environments of the CuII centres are different. In (I), the CuII centre, sitting on a general position, has a square‐pyramidal environment. The two independent benzene‐1,2,4,5‐tetracarboxylate (btc) anions rest on centres of inversion. The CuII cation in (II) is located on a twofold axis in a square‐planar coordination. The H2en cation is on an inversion centre and the btc ligand is split by a mirror plane. Extensive hydrogen‐bonding interactions between the complexes, H2en cations and water molecules lead to the formation of three‐dimensional supramolecular structures. 相似文献
16.
Claude Didierjean Julien Marin Emmanuel Wenger Jean‐Paul Briand Andr Aubry Gilles Guichard 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o200-o203
X‐ray studies reveal that tert‐butyl (6S)‐6‐isobutyl‐2,4‐dioxopiperidine‐1‐carboxylate occurs in the 4‐enol form, viz. tert‐butyl (6S)‐4‐hydroxy‐6‐isobutyl‐2‐oxo‐1,2,5,6‐tetrahydropyridine‐1‐carboxylate, C14H23NO4, when crystals are grown from a mixture of dichloromethane and pentane, and has an axial orientation of the isobutyl side chain at the 6‐position of the piperidine ring. Reduction of the keto functionality leads predominantly to the corresponding β‐hydroxylated δ‐lactam, tert‐butyl (4R,6S)‐4‐hydroxy‐6‐isobutyl‐2‐oxopiperidine‐1‐carboxylate, C14H25NO4, with a cis configuration of the 4‐hydroxy and 6‐isobutyl groups. The two compounds show similar molecular packing driven by strong O—H⋯O=C hydrogen bonds, leading to infinite chains in the crystal structure. 相似文献
17.
John F. Gallagher Claire M. Coleman Donal F. O'Shea 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o149-o151
The molecule of the title compound, C19H27NO3, is essentially planar, with all non‐H atoms within 0.2 Å of the nine‐membered indole plane, except for the three tert‐butyl C atoms. The C5 pentyl chain is in an extended conformation, with three torsion angles of 179.95 (13), 179.65 (13) and −178.95 (15)° (the latter two angles include the C atoms of the C5 chain only). Three intramolecular C—H⋯Ozdbnd;C contacts are present (C⋯O < 3.05 Å and C—H⋯O > 115°), and an intermolecular C—H⋯Ozdbnd;C contact and π–π stacking complete the intermolecular interactions. 相似文献
18.
Simon Jones J. C. Christian Atherton Mark R. J. Elsegood William Clegg 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):881-883
In the crystal structure of the title compound, C18H14O4, there are two independent molecules, both of which are exactly centrosymmetric and therefore have a transoid arrangement of the ester substituents. The planes of these are inclined at 63.90 (4) and 61.02 (5)° to the anthracene central ring in the two molecules because of steric interactions, preventing electronic delocalization. The observed conformation is in agreement with molecular‐modelling calculations for the isolated molecule, indicating no major influence from crystal‐packing forces. 相似文献
19.
Daniel E. Lynch Ian McClenaghan 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e586-e586
The structure of the title compound, C12H12N2O2S, (I), comprises molecules that form dimers via N—H?N hydrogen‐bonding interactions and then construct the overall network through N—H?O associations. The dihedral angle between the phenyl and thiazole rings is 42.41 (6)°. 相似文献
20.
M. Ramos Silva A. Matos Beja J. A. Paixo L. Alte da Veiga A. J. F. N. Sobral A. M. d'A. Rocha Gonsalves 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1263-1264
In the title compound, C16H17NO4, the benzyloxycarbonyl group is anti to the pyrrolic N atom. The molecules are joined into head‐to‐head dimers by hydrogen bonds involving the carboxylic acid groups. There is orientational disorder of these groups over two positions with approximately equal occupancy. A weaker hydrogen bond between the pyrrolic N atom and the carbonyl O atom of the benzyloxycarbonyl group joins the dimers into chains running parallel to the [110] direction. 相似文献