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1.
Mario Cetina Marijana Juki Vladimir Rapi Amalija Golobi
《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):m212-m214
In the title compound, [Fe(C7H7O2)2], the cyclopentadienyl rings and the two attached methoxycarbonyl groups, in an anti arrangement, form an extended π‐conjugated system. The Fe—C distances range from 2.035 (3) to 2.061 (3) Å and the average value of the C—C bond lengths in the two cyclopentadienyl rings is 1.419 (5) Å. The rings are almost parallel to one another [1.0 (2)°] and are mutually twisted from an eclipsed conformation by only 1.8 (3)° (average value). The methoxycarbonyl groups are twisted out of the plane of the cyclopentadienyl rings by 6.5 (4) and 15.7 (4)°, respectively. The molecules are joined into dimers by intermolecular C—H⃛O hydrogen bonds that form ten‐membered rings. The same types of hydrogen bonds form eight‐membered rings and infinite chains along the b axis. 相似文献
2.
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
3.
Viktor Vrbel Jozef Lehotay Drahomír Oktavec tefan Marchalín 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1073-1074
The crystal structure of the title compound, C20H23N3O7, consists of relatively isolated molecules. The substituted 1,4‐dihydropyridine ring adopts a flattened boat conformation. Both ester groups, at positions 3 and 5, have cis,cis geometry. The phenyl ring is nearly planar and is approximately perpendicular to the 1,4‐dihydropyridine ring (dihedral angle 87.70°). 相似文献
4.
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
5.
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
6.
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
7.
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
8.
Li Feng Zhi‐Ming Li Zhen‐Xia Chen Yong‐Sheng Tan Lin‐Hong Weng Feng‐Gang Tao 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o680-o681
The title compound, C38H32BrNO6, is a new photochromic tetrahydroazepinoisoquinoline (THAI). The longest spiro bond [1.589 (4) Å] can be broken very easily by UV light, leading to ring opening. This explains the photochromic behaviour. 相似文献
9.
Jaromír Marek Kamila Lunerov Jaromír Touek Vclav Suchý Radek Marek 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(6):o386-o389
The crystal structures of 2′,4′‐dihydroxy‐3‐methoxy‐α,β‐dihydrochalcone, C16H16O4, and 2′,4‐dihydroxy‐α,β‐dihydrochalcone, C15H14O3, have been determined. In both compounds, the structure consists of two nearly planar six‐membered aromatic rings connected by a propanal chain, which is bent in the methoxy compound and almost straight in the other compound. In the crystal structures, the molecular units of both compounds are linked by O—H⋯O hydrogen bonds to form infinite one‐dimensional chains. Hydrogen bonds and C—H⋯O contacts in the crystal structures were studied by topological analysis of charge density based on Hartree–Fock calculations. Almost all of the investigated C—H⋯O contacts should be characterized as weak hydrogen bonds. 相似文献
10.
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
11.
Michael Bolte Alexander Degen Stephan Rühl 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):444-445
The reaction of dimedone with 2,6‐dichlorobenzaldehyde leads to the title compound, C23H26Cl2O4. In principle, the reaction could yield eight different stereoisomers. We have found four of them in the same crystal as two enantiomeric pairs of diastereomers, which means that the asymmetric unit is built up of two different diastereomers. Two of the three chiral centres display the same configuration, while the third is different in the two molecules in the asymmetric unit. The packing of the molecules is stabilized by hydrogen bonds between the hydroxy group and the carbonyl group attached to the cyclohexene ring, forming chains in which the different diastereomers alternate. 相似文献
12.
S. V. Shishkina O. V. Shishkin I. V. Ukrainets N. A. Jaradat O. V. Gorokhova 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e168-e169
The two bicyclic fragments of the title compound, C22H20N4O4, are individually planar and are turned with respect to each other by 77.8 (2)°. The formation of intramolecular O—H?O and N—H?O hydrogen bonds causes considerable changes in the bond lengths within the amidopyridine fragment. 相似文献
13.
Shaoming Duan Ronald J. Baker John Masnovi 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):99-101
The structure of 9‐phenyl‐3,4,4a,9a‐tetrahydrotriptycene, C26H22, (I), exhibits regiochemistry consistent with a stepwise mechanism for its formation from photocycloaddition of 1,3‐cyclohexadiene and 9‐phenylanthracene. Bond distances involving the bridgehead C atoms are similar in (I) and the hydrogenated derivative, 9‐phenyl‐1,2,3,4,4a,9a‐hexahydrotriptycene, C26H24, (II), with bonds to the quaternary‐C atoms exhibiting significant elongation [1.581 (2) Å in (I) and 1.585 (2) Å in (II)]. The molecular geometry precludes significant σ–π overlap between the phenyl groups and the interannular bonds in both compounds, indicating that the origin of the bond lengthening is steric in nature. 相似文献
14.
Anthony Linden Cihat afak Frat Aydn 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(10):o711-o713
The title compound, C20H21ClN2O5, has potential calcium modulatory properties. The 1,4‐dihydropyridine ring has the usual shallow boat conformation. The 2‐chloro‐5‐nitrophenyl ring is oriented such that the chloro substituent is in a synperiplanar orientation with respect to the 1,4‐dihydropyridine ring plane, while the nitro substituent sits over the 1,4‐dihydropyridine ring. The cyclohexenone ring has a conformation that is approximately half‐way between that of an envelope and that of a half‐chair. The molecules are linked into chains by intermolecular N—H⋯O hydrogen bonds. 相似文献
15.
L. Vijayalakshmi V. Parthasarathi Vipul Vora Bhavik Desai Anamik Shah 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):817-818
In the title salt, C5H12N+·C29H23O6?, both benzopyran systems are planar. Intermolecular N—H?O hydrogen bonds and a short O—H?O intramolecular hydrogen bond are observed in the structure. 相似文献
16.
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
17.
Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o580-o582
In the title compound, C15H24O3, derived from a naturally occurring sesquiterpenoid, the asymmetric unit consists of two molecules differing by 167.4 (8)° in the rotational conformation of the carboxyl group. Each molecule aggregates separately with its own type as carboxyl‐to‐ketone hydrogen‐bonding catemers [O⋯O = 2.715 (6) and 2.772 (6) Å, and O—H⋯O = 169 and 168°]. This generates two crystallographically independent single‐strand hydrogen‐bonding helices passing through the cell in the b direction, with opposite end‐to‐end orientations. One intermolecular C—H⋯O=C close contact exists for the carboxyl group of one of the molecules. The structure is isostructural with that of a closely related unsaturated keto acid reported previously. 相似文献
18.
19.
Fen Sun Yan‐Tuan Li Zhi‐Yong Wu Da‐Qi Wang Jian‐Min Dou 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):m60-m62
The structure of the title compound, (C5H12N)4[V10O26(CH3O)2], reveals the presence of four protonated piperidinium cations and a [{V10O26}(OCH3)2]4− polyanion having an embedded centre of inversion. The compound is distinguished by presenting, in contrast with other anionic decavanadates, two methoxy groups bridging the outermost V atoms, and it becomes the first example of this type among reported decavanadates. 相似文献
20.
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