共查询到20条相似文献,搜索用时 15 毫秒
1.
Marcin Palusiak Izabela Janowska Janusz Zakrzewski Sawomir J. Grabowski 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(1):m55-m57
In the title compound, [Fe(C5H5)(C12H19NO)]I, the ferrocene moiety has an eclipsed conformation, with mean Fe—C bond lengths of 2.031 (4) and 2.020 (6) Å for the substituted and unsubstituted cyclopentadienyl rings. The pyrrolidinium heterocycle adopts an envelope conformation and has its 1‐ and 2‐substituents in a relative trans disposition. Strong (+/−)‐charge‐assisted N—H·I and C—H·I hydrogen bonds are present. The crystal structure is also stabilized by weak C—H·O interactions. 相似文献
2.
Ming Sun Alasdair C. Macculloch Thomas A. Hamor Richard T. Walker 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):116-117
The pyrimidine ring of the title compound, C11H16N2O5S·H2O, is planar to within 0.026 (1) Å and makes an angle of 77.73 (8)° with the mean plane of the thiosugar ring. In terms of standard nucleoside nomenclature, this ring has a C1′‐exo,C2′‐endo conformation. The O5′—C5′—C4′—C3′ torsion angle is ?167.4 (2)° and the glycosidic S4′—C1′—N1—C2 torsion angle is ?101.8 (2)° (anti). 相似文献
3.
Jing‐Jing Nie Duan‐Jun Xu Zi‐Qiang Hu Yuan‐Zhi Xu Jing‐Yun Wu Michael Y. Chiang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o106-o107
The title chiral compound, 3‐aminocarbonyl‐1,2,2‐trimethylcyclopentane‐1‐carboxylic acid, C10H17NO3, was prepared from (1R,3S)‐camphoric acid. The five‐membered ring adopts a conformation which is intermediate between a twist and an envelope. Elongations of the C—C bonds and contractions of the C—C—C bond angles are observed within the five‐membered ring. A 1H NMR spectrum was recorded to assist in distinguishing the amide group from the carboxyl group. 相似文献
4.
Wenhui Zhang Bruce C. Noll Anthony S. Serianni 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(10):o578-o581
The β‐pyranose form, (III), of 3‐deoxy‐d ‐ribo‐hexose (3‐deoxy‐d ‐glucose), C6H12O5, crystallizes from water at 298 K in a slightly distorted 4C1 chair conformation. Structural analyses of (III), β‐d ‐glucopyranose, (IV), and 2‐deoxy‐β‐d ‐arabino‐hexopyranose (2‐deoxy‐β‐d ‐glucopyranose), (V), show significantly different C—O bond torsions involving the anomeric carbon, with the H—C—O—H torsion angle approaching an eclipsed conformation in (III) (−10.9°) compared with 32.8 and 32.5° in (IV) and (V), respectively. Ring carbon deoxygenation significantly affects the endo‐ and exocyclic C—C and C—O bond lengths throughout the pyranose ring, with longer bonds generally observed in the monodeoxygenated species (III) and (V) compared with (IV). These structural changes are attributed to differences in exocyclic C—O bond conformations and/or hydrogen‐bonding patterns superimposed on the direct (intrinsic) effect of monodeoxygenation. The exocyclic hydroxymethyl conformation in (III) (gt) differs from that observed in (IV) and (V) (gg). 相似文献
5.
Ming Sun Alasdair C. Macculloch Thomas A. Hamor Richard T. Walker 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1492-1493
The pyrimidine ring of the title compound, C10H14N2O5S, is planar to within 0.024 (1) Å and makes an angle of 75.46 (10)° with the mean plane of the thiosugar ring. In terms of standard nucleoside nomenclature, this ring has the C3′‐endo conformation. The O5′—C5′—C4′—C3′ torsion angle is 166.5 (3)° and the glycosidic torsion angle S4′—C1′—N1—C2 is ?52.1 (2)° (syn). 相似文献
6.
Rafal Kruszynski Wojciech Czestkowski 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(5):402-406
The title compound, C21H26FN3O7, is assembled by N—H...O and O—H...O hydrogen bonds into well‐separated two‐dimensional layers of about 15 Å thickness. The crescent conformation of the molecules is stabilized by weak intramolecular C—H...O and C—H...F hydrogen bonds. The uridine moiety adopts an anti conformation. The ribofuranose ring exists in an envelope conformation. All the endocyclic uracil bonds are shorter than normal single C—N and C—C bonds, and five of them have comparable lengths, which implies a considerable degree of delocalization of the electron density within this ring. 相似文献
7.
Yang-Rong Xu Jing-Jing Yang Juan Liu Gui-Ge Hou Qing-Guo Meng 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(6):498-503
Ocotillol‐type saponins have a wide spectrum of biological activities. Previous studies indicated that the configuration at the C24 position may be responsible for their stereoselectivity in pharmacological action and pharmacokinetics. Natural ocotillol‐type saponins share a 20(S)‐form but it has been found that the 20(R)‐stereoisomers have different pharmacological effects. The semisynthesis of 20(R)‐ocotillol‐type saponins has not been reported and it is therefore worthwhile clarifying their crystal structures. Two C24 epimeric 20(R)‐ocotillol‐type saponins, namely (20R,24S)‐20,24‐epoxydammarane‐3β,12β,25‐triol, C30H52O4, (III), and (20R,24R)‐20,24‐epoxydammarane‐3β,12β,25‐triol monohydrate, C30H52O4·H2O, (IV), were synthesized, and their structures were elucidated by spectral studies and finally confirmed by single‐crystal X‐ray diffraction. The (Me)C—O—C—C(OH) torsion angle of (III) is 146.41 (14)°, whereas the corresponding torsion angle of (IV) is −146.4 (7)°, indicating a different conformation at the C24 position. The crystal stacking in (III) generates an R44(8) motif, through which the molecules are linked into a one‐dimensional double chain. The chains are linked via nonclassical C—H…O hydrogen bonds into a two‐dimensional network, and further stacked into a three‐dimensional structure. In contrast to (III), epimer (IV) crystallizes as a hydrate, in which the water molecules act as hydrogen‐bond donors linking one‐dimensional chains into a two‐dimensional network through intermolecular O—H…O hydrogen bonds. The hydrogen‐bonded chains extend helically along the crystallographic a axis and generate a C44(8) motif. 相似文献
8.
S. Thamotharan V. Parthasarathi Subodh Kumar Vijay Kumar Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o335-o337
The central ring of the anthrone system in the title compound, C17H14O4, has a shallow envelope conformation, and each of the two outer rings is inclined at an angle of 17.41 (3)°. In the solid state, the molecules exist as centrosymmetrically related O—H⃛O hydrogen‐bonded dimers. Two intramolecular O—H⃛O hydrogen bonds, involving the central carbonyl O atom and having a graph‐set motif of S(6), are observed. These intramolecular interactions lead co‐operatively to an O—H⃛O⃛H—O pattern that has a binary graph‐set motif of (10). 相似文献
9.
Maria Gdaniec Igor Bensemann Tadeusz Pooski 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o215-o216
Hindered rotation about the partial double C—N bonds between the amine and pyridine moieties in the title molecule, C16H14N4, results in two different conformations of the N‐aryl‐2‐aminopyridine units. One, assuming an E conformation, is involved in a pair of N—H⋯N hydrogen bonds that generate a centrosymmetric (8) motif. The second, adopting a Z conformation, is not engaged in any hydrogen bonding and is flattened, the dihedral angle between the benzene and pyridine rings being 12.07 (7)°. This conformation is stabilized by an intramolecular C—H⋯N interaction [C⋯N = 2.9126 (19) Å, H⋯N = 2.31 Å and C—H⋯N = 120°]. 相似文献
10.
Naiem Ahmad Wani Vivek Kumar Gupta Rajni Kant Subrayashastry Aravinda Rajkishor Rai 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(8):776-779
The crystal structure of N‐[(1‐{2‐oxo‐2‐[2‐(pyrazin‐2‐ylcarbonyl)hydrazin‐1‐yl]ethyl}cyclohexyl)methyl]pyrazine‐2‐carboxamide monohydrate (Pyr‐Gpn‐NN‐NH‐Pyr·H2O), C19H23N7O3·H2O, reveals an unusual trans–gauche (tg−) conformation for the gabapentin (Gpn) residue around the Cγ—Cβ (θ1) and Cβ—Cα (θ2) bonds. The molecular conformation is stabilized by intramolecular N—H...N hydrogen bonds and weak C—H...O interactions. The packing of the molecules in the crystal lattice shows a network of strong N—H...O and O—H...O hydrogen bonds together with weak C—H...O and π–π inteactions. 相似文献
11.
Shusheng Zhang Zhongwei Wang Ming Li Kui Jiao Ibrahim Abdul Razak S. Shanmuga Sundara Raj Hoong‐Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):566-568
In both the title structures, O‐ethyl N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐d ‐glucopyranosyl)thiocarbamate, C17H25NO10S, and O‐methyl N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐d ‐glucopyranosyl)thiocarbamate, C16H23NO10S, the hexopyranosyl ring adopts the 4C1 conformation. All the ring substituents are in equatorial positions. The acetoxymethyl group is in a gauche–gauche conformation. The S atom is in a synperiplanar conformation, while the C—N—C—O linkage is antiperiplanar. N—H?O intermolecular hydrogen bonds link the molecules into infinite chains and these are connected by C—H?O interactions. 相似文献
12.
E. Mothi Mohamed Samraj Muralidharan Krishnaswamy Panchanatheswaran Rengan Ramesh John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):o367-o369
Molecules of the title compound, alternatively called (R,R)‐N,N′‐bis(3‐methoxysalicylidene)‐trans‐cyclohexane‐1,2‐diamine, C22H26N2O4, contain two intramolecular O—H⃛N hydrogen bonds and adopt a conformation with approximate twofold rotational symmetry. The molecules are linked by three C—H⃛O hydrogen bonds [H⃛O = 2.45–2.55 Å, C⃛O = 3.329 (2)–3.398 (2) Å and C—H⃛O = 142–172°] into a continuous framework. 相似文献
13.
Ying Fu Yin‐Xia He Hong‐Xia Hou Wen‐Bo Zhu Hu‐Lin Li Chao Wu Fang‐Yan Xian 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(3):282-284
2,2′‐Anhydro‐1‐(3′,5′‐di‐O‐acetyl‐β‐D‐arabinofuranosyl)uracil, C13H14N2O7, was obtained by refluxing 2′,3′‐O‐(methoxymethylene)uridine in acetic anhydride. The structure exhibits a nearly perfect C4′‐endo (4E) conformation. The best four‐atom plane of the five‐membered furanose ring is O—C—C—C, involving the C atoms of the fused five‐membered oxazolidine ring, and the torsion angle is only −0.4 (2)°. The oxazolidine ring is essentially coplanar with the six‐membered uracil ring [r.m.s. deviation = 0.012 (5) Å and dihedral angle = −3.2 (3)°]. The conformation at the exocyclic C—C bond is gauche–trans which is stabilized by various C—H...π and C—O...π interactions. 相似文献
14.
Frank Seela Anup M. Jawalekar Simone Budow Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(9):o562-o564
In the title compound, 4‐amino‐1‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐6‐methylsulfanyl‐1H‐pyrazolo[3,4‐d]pyrimidine, C11H16N5O3S, the conformation of the glycosidic bond is between anti and high anti. The 2′‐deoxyribofuranosyl moiety adopts the C3′‐exo–C4′‐endo conformation (3T4, S‐type sugar pucker), and the conformation at the exocyclic C—C bond is +sc (+gauche). The exocyclic 6‐amine group and the 2‐methylsulfanyl group lie on different sides of the heterocyclic ring system. The molecules form a three‐dimensional hydrogen‐bonded network that is stabilized by O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds. 相似文献
15.
16.
Daniel Fernndez Daniel Vega 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o661-o663
The title compound, C8H19NO7P2, is a member of the bisphosphonate family of therapeutic compounds. PHPBP has inner‐salt character, consisting of a negatively charged PO3 group and a positively charged N atom. The six‐membered piperidine ring adopts an almost‐perfect chair conformation. The hydroxyl group and the N atom have gauche and trans conformations in relation to the O—C—C—C—N backbone, respectively. Hydrogen bonding is the main contributor to the packing in the crystal, which consists of head‐to‐head dimers formed through phosphonyl–phosphonyl hydrogen bonds, while O—H⋯O and N—H⋯O interactions join the dimers into a plane parallel to crystallographic b and c axes. 相似文献
17.
Sandra L. Gmez Alirio Palma Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(5):o157-o160
The title compound, C15H16N2O, crystallizes in the space group P212121 with Z′ = 1. The seven‐membered ring adopts a chair‐type conformation with the hydroxy and pyridyl substituents in equatorial sites. Molecules are linked into a three‐dimensional framework structure by a combination of O—H...N, C—H...O and C—H...π(arene) hydrogen bonds, but N—H...O and N—H...π(arene) interactions are absent from the structure. Comparisons are made with some related compounds. 相似文献
18.
Martín Hernndez‐Jurez Veronica Salazar‐Pereda Itzia I. Padilla‐Martínez Efrn V. García‐Bez 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(12):m367-m369
In the title complex salt, [Ir(C5H4O)(C16H22N6)(CO)](CF3O3S), the IrIII centre adopts a distorted octahedral geometry with a facial coordination of the tris(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methane ligand. The C—C distances of the iridacycle are in agreement with its iridacyclohexa‐2,5‐dien‐4‐one nature, which presents a nonsymmetric boat‐like conformation with the C—Ir—C vertex more bent than the C—C(=O)—C vertex. The supramolecular architecture is mainly directed by CO...CO and CO...π and Csp3—H...O interactions, the arrangement of which depends on the anion. 相似文献
19.
Kandasamy Chinnakali S. Shanmuga Sundara Raj Hoong‐Kun Fun Kamaraj Sriraghavan Vayalakkavoor T. Ramakrishnan 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):227-228
In the title compound, C17H21NO3S, the S atom is in a distorted tetrahedral geometry and the N atom exhibits sp2 character. The antiperiplanar conformation is observed for the N and hydroxyl‐O atoms and the torsion angle around the N—C linkage is ?136.3 (2)°. The molecules are linked by O—H?O intermolecular hydrogen bonds to form an infinite one‐dimensional chains along the c axis. 相似文献
20.
K. Rajalakshmi Vasantha Pattabhi C. S. Venkatesan G. Nadamuni A. Srikrishna 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):e307-e308
In the title compound, C29H42O4·H2O, cyclohexane rings A and B are in the sofa conformation, ring C is in a chair conformation and the five‐membered ring D is in an envelope conformation. The structure is stabilized by inter‐ and intramolecular C—H?O and O—H?O hydrogen bonds. 相似文献