共查询到20条相似文献,搜索用时 31 毫秒
1.
Edward E. vila Asilo J. Mora Gerzon E. Delgado Belkis M. Ramírez Alí Bahsas Sonia Koteich 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(10):o759-o761
In the title compound, C7H13NO2·0.5H2O, cis‐4‐aminocyclohexanecarboxylic acid exists as a zwitterion and co‐crystallizes with water molecules in a 2:1 amino acid–water ratio. The cyclohexane ring adopts a chair conformation, with the carboxylate and ammonium groups in axial and equatorial positions, respectively. The basic motif in the crystal structure is a sandwich structure, formed by two amino acid units linked by head‐to‐tail hydrogen bonds. Hydrogen bonds of the type N+—H⋯O—C—O− link these motifs, forming helicoidally extended chains running along the c axis. The water molecule lies on a twofold axis and interacts with the chains by means of O—H⋯O hydrogen bonds. 相似文献
2.
Anwar Usman Ibrahim Abdul Razak Suchada Chantrapromma Hoong‐Kun Fun Tarun K. Sarkar Sankar Basak Gur Dayal Nigam 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1116-1117
In the title compound, C16H19ClN2O4, the pyridine ring is nearly planar, the piperidine ring is non‐planar and the cyclohexane ring adopts a screw‐boat conformation. The carboxylate group makes a dihedral angle of 80.9 (2)° with the least‐squares plane through the cyclohexane ring. 相似文献
3.
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
4.
Simn Hernndez‐Ortega Federico Jimnez‐Cruz Hctor Ríos‐Olivares Manuel Rubio‐Arroyo 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):425-427
The title compound, ethyl 2‐hydroxy‐4‐oxo‐2‐phenylcyclohexanecarboxylate, C15H18O4, was obtained by a Michael–Aldol condensation and has the cyclohexanone in a chair conformation. The attached hydroxy, ethoxycarbonyl and phenyl groups are disposed in β‐axial, β‐equatorial and α‐equatorial configurations, respectively. An intermolecular hydrogen bond, with an O?O distance of 2.874 (2) Å, links the OH group and the ring carbonyl. Weak intermolecular C—H?O=C (ester and ketone), O—H?O=C (ketone) and C—H?OH hydrogen bonds exist. 相似文献
5.
Raymond C. Bott Graham Smith Urs D. Wermuth 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1505-1506
The crystal structure determination of the molecular proton‐transfer adduct of Kemp's triacid (cis‐cis‐1,3,5‐trimethylcyclohexane‐1,3,5‐tricarboxylic acid, KTA) with 2‐aminopyridine (2‐APY), namely 2‐aminopyridinium 3,5‐dicarboxy‐1,3,5‐trimethylcyclohexanecarboxylate, 2‐APY+·KTA? or C5H7N2+·C12H17O6?, has revealed a centrosymmetric hydrogen‐bonded cyclic KTA homodimer repeating unit [O?O 2.524 (4) Å] linked into a polymer structure through the pyridinium and amino groups of the 2‐APY molecule [O?N 2.736 (4), 2.989 (4) and 2.999 (4) Å]. 相似文献
6.
Jacob M. Newman Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1152-1154
The structures are presented for both diastereomers of the title compound, C15H20O4, produced by base‐catalyzed self‐condensation of cyclohexane‐cis‐1,2‐dicarboxylic anhydride in refluxing triethylamine. Equilibration of either diastereomer under the condensation conditions yielded the same 5:3 mixture. In the crystal, one diastereomer, (II), is ordered, while the other, (I), displays both flexional ring disorder and carboxyl disorder; both aggregate as centrosymmetric hydrogen‐bonded dimers [for (I), O?O = 2.680 (2) Å; for (II), O?O = 2.635 (4) Å]. 相似文献
7.
Latif Kelebekli Yunus Kara Metin Balci Ertan ahin 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o432-o434
In the title compound, C16H20Cl2O8, the bicyclic system contains a central non‐planar cyclohexane ring which is fused to a cyclobutane moiety. The cyclohexane ring has a chair conformation and the whole system adopts a syn conformation. The structure provides information on the stereochemical course of the chlorination, photo‐oxidation and hydroxylation steps of the reaction. 相似文献
8.
Swastik Mondal Monika Mukherjee Arnab Roy Debabrata Mukherjee 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):o132-o134
In the title tricyclic keto‐diester, C20H24O6, a potential intermediate in the synthesis of bioactive podocarpic acid, the outer cyclohexane ring (in a chair conformation) is cis fused to the central cyclohexanone ring (in a half‐chair conformation). The conformational analysis of the compound, investigated by semi‐empirical quantum mechanical AM1 calculations, shows a good agreement with the X‐ray structure, except for the orientation of the methyl, methoxyphenyl and methoxycarbonyl substituents. 相似文献
9.
Jakub Wojciechowski Henryk Krawczyk Marcin
liwiski Wojciech M. Wolf 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(6):o351-o353
The title compound, C11H16O3, adopts a conformation in which the δ‐valerolactone and cyclohexane rings are almost coplanar with one another. The β‐methoxy substituent occupies an axial position with respect to the cyclohexane ring. The δ‐valerolactone moiety adopts a half‐chair arrangement, while the cyclohexane ring exists in a chair conformation. 相似文献
10.
Michael Bolte Alexander Degen Ernst Egert 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1338-1342
We have determined the crystal structures of bicyclo[2.2.1]hept‐2‐ene‐endo‐cis‐5,6‐dicarboxylic anhydride, C9H8O3, (I), 1,2,3,4,7,7‐hexachlorobicyclo[2.2.1]hept‐2‐ene‐endo‐cis‐5,6‐dicarboxylic anhydride diethyl ether solvate, C9H2Cl6O3·0.16C4H10O, (II), bicyclo[2.2.1]hept‐2‐ene‐endo‐cis‐5,6‐dicarboxylic acid, C9H10O4, (III), 1,2,3,4,7,7‐hexachlorobicyclo[2.2.1]hept‐2‐ene‐endo‐cis‐5,6‐dicarboxylic acid, C9H4Cl6O4, (IVa) and (IVb), and ethyl 1,2,3,4,7,7‐hexachloro‐6‐carboxybicyclo[2.2.1]hept‐2‐ene‐endo‐cis‐5‐carboxylate monohydrate, C11H8Cl6O4·H2O, (V). Compounds (I) and (II) were prepared by a standard Diels–Alder reaction from maleic anhydride and cyclopentadiene or hexachlorocyclopentadiene, respectively. The crystal‐growing processes of these compounds led to surprising results: rapid recrystallization of (I) from diethyl ether and (II) from petroleum ether gave crystals of these compounds, however, crystallization by slow evaporation techniques using common solvents yielded new compounds in which the five‐membered heterocycle has been cleaved. 相似文献
11.
Henryk Krawczyk Marcin
liwiski Wojciech M. Wolf 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o897-o899
The title compound, C11H16O2, adopts a semifolded conformation with the δ‐lactone and cyclohexane rings almost perpendicular to one another. The β‐methyl substituent occupies an axial position with respect to the cyclohexane ring. The δ‐lactone moiety adopts a slightly distorted half‐chair arrangement, while the cyclohexane ring exists in an almost ideal chair conformation. 相似文献
12.
Hans‐Georg Weinig Ulrich Koert Burkhard Ziemer 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):e218-e218
The title compound, 2,3‐dimethoxy‐2,3‐dimethyl‐5,6,7,8‐tetrahydro‐4‐oxachroman, C12H22O4, was synthesized as a model compound for substituted diequatorial fixed vicinal trans‐cyclohexanediols. 相似文献
13.
Anthony Linden Agnieszka Majchrzak Jovita Cavegn Grzegorz Mloston Heinz Heimgartner 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o480-o484
The four oligosulfanes, bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)disulfane, C16H24Cl2O2S2, (III), 1,3‐bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)trisulfane, C16H24Cl2O2S3, (V), 1,4‐bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)tetrasulfane, C16H24Cl2O2S4, (VII), and 1,6‐bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)hexasulfane, C16H24Cl2O2S6, (VIII), all have similar geometric parameters, with the C—C bond lengths involving the chloro‐substituted cyclobutanyl C atom being elongated to about 1.59 Å. There are two molecules in the asymmetric units of the tri‐ and tetrasulfanes, and the molecules in the latter compound have local C2 symmetry. The molecule of the hexasulfane has crystallographic C2 symmetry. Most of the cyclobutanyl rings are not perfectly planar and have slight but varying degrees of distortion towards a flattened tetrahedron. The polysulfane chain in each structure has a helical conformation, with each additional S atom in the chain adding approximately one quarter of a turn to the helix. 相似文献
14.
Lars G. J. Hammarstrm Tao Zhang Jos Giralds Mark L. McLaughlin Damon R. Billodeaux Frank R. Fronczek 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1484-1486
The carboxy group of 2‐methyl‐N‐[(2‐nitrophenyl)sulfonyl]alanine, C10H12N2O6S, forms centrosymmetric hydrogen‐bonded dimers with an O?O distance of 2.629 (2) Å and an intramolecular N—H?O(nitro) hydrogen bond N?O distance of 2.823 (2) Å. 1‐[(2‐Nitrophenyl)sulfonylamino]cyclohexanecarboxylic acid, C13H16N2O6S, has Z′ = 2 and forms similar interactions. 相似文献
15.
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
16.
Zhi‐Feng Li Hong‐Zhen Xie Yue‐Qing Zheng 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):m455-m457
In the title compound, [Ni2(C12H8O12)(C12H8N2)2]n, the 3,6‐dicarboxycyclohexane‐1,2,4,5‐tetracarboxylate (H2chhc4−) anion has crystallographically imposed C2 symmetry and bridges the six‐coordinate Ni atoms to generate polymeric [Ni2(H2chhc)2/2(C12H8N2)2] chains extending in the [010] direction. The coordination polymer chains are linked into a three‐dimensional framework by O—H⋯O and C—H⋯O hydrogen bonds. 相似文献
17.
Michael Bolte Alexander Degen 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):e340-e340
The structure of the title compound, C8H10O4, previously determined by Küppers & Kim [Acta Cryst. (1993), C 49 , 1218–1220] has been redetermined at 173 K. The cyclohexene ring exhibits a half‐chair conformation. The molecular geometry and the crystal packing, which is stabilized by two hydrogen bonds, agree well with the room‐temperature structure determination. 相似文献
18.
Markus Pietsch Martin Nieger Michael Gütschow 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):o147-o151
The title compounds, tert‐butyl 6‐benzyl‐2‐(3,3‐diethylureido)‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine‐3‐carboxylate, C24H33N3O3S, (I), 7‐benzyl‐2‐diethylamino‐5,6,7,8‐tetrahydro‐3‐oxa‐9‐thia‐1,7‐diazafluoren‐4‐one, C20H23N3O2S, (II), and N‐(7‐benzyl‐4‐oxo‐5,6,7,8‐tetrahydro‐4H‐3,9‐dithia‐1,7‐diazafluoren‐2‐yl)benzamide, C23H19N3O2S2, (III), form monoclinic crystal systems. In (I) and (II), the molecules are linked into a three‐dimensional framework by weak intermolecular C—H⋯O=C hydrogen bonds, whereas in (III) stronger intermolecular N—H⋯O=C interactions are observed. The conformation of (I) is further stabilized by an intramolecular N—H⋯O=C hydrogen bond, which effects the planarity of the ureidothiophenecarboxylate moiety. 相似文献
19.
Swastik Mondal Monika Mukherjee Arnab Roy Debabrata Mukherjee Madeleine Helliwell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o474-o476
In the title compound, C13H22O3, the asymmetric unit has two independent molecules linked by a strong O—H?O hydrogen bond. The cyclohexane ring is trans fused to the cyclopentane ring bridged through an ethyl moiety. The hydroxyl groups act as donors as well as acceptors, resulting in an extensive two‐dimensional hydrogen‐bonded network in the (011) plane. Intermolecular O—H?O bonds between centrosymmetrically related molecules form a four‐membered supramolecular assembly, leading to infinite chains parallel to the [01] direction, crosslinked in the [100] direction. 相似文献
20.
Ramaiyer Venkatraman Paresh Chandra Ray Frank R. Fronczek 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o633-o635
Hexamethylenetetramine and rac‐trans‐1,2‐cyclohexanedicarboxylic acid crystallize in a 1:1 ratio as a neutral molecular adduct, C6H12N4·C8H12O4. Two dicarboxylic acid molecules and two tetramine molecules form a hydrogen‐bonded ring, in the shape of a rhombus, which lies on a crystallographic twofold axis bisecting the two diacid molecules. The O—H⋯N hydrogen bonds have lengths 2.6808 (19) and 2.6518 (19) Å, and, in each ring, both acid molecules have the same handedness. 相似文献