共查询到20条相似文献,搜索用时 31 毫秒
1.
William T. A. Harrison R. Alan Howie Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):m351-m354
The title compounds, [Sn(C6H5)2(C5H4S5)] and [Sn(C5H4S5)2], respectively, are of interest because they can be regarded as intermediate in nature between chelates and heterocyclic compounds containing the C3S5 fragment. In contrast with the essentially normal bond lengths and angles within the molecules, the molecular conformations are somewhat unexpected, as are the intermolecular contacts found in the case of the latter compound. 相似文献
2.
Frank Seela Matthias Zulauf Hans Reuter Guido Kastner 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):489-491
The isomorphous structures of the title molecules, 4‐amino‐1‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐3‐iodo‐1H‐pyrazolo‐[3,4‐d]pyrimidine, (I), C10H12IN5O3, and 4‐amino‐3‐bromo‐1‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐1H‐pyrazolo[3,4‐d]pyrimidine, (II), C10H12BrN5O3, have been determined. The sugar puckering of both compounds is C1′‐endo (1′E). The N‐glycosidic bond torsion angle χ1 is in the high‐anti range [?73.2 (4)° for (I) and ?74.1 (4)° for (II)] and the crystal structure is stabilized by hydrogen bonds. 相似文献
3.
Clair Bilton Judith A. K. Howard N. N. Laxmi Madhavi Gautam R. Desiraju Frank H. Allen 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1356-1358
The title compounds, C8H10O2, (I), and C12H14O2, (II), occurred as by‐products in the controlled synthesis of a series of bis(gem‐alkynols), prepared as part of an extensive study of synthon formation in simple gem‐alkynol derivatives. The two 4‐(gem‐alkynol)‐1‐ones crystallize in space group P21/c, (I) with Z′ = 1 and (II) with Z′ = 2. Both structures are dominated by O—H?O=C hydrogen bonds, which form simple chains in the cyclohexane derivative, (I), and centrosymmetric dimers, of both symmetry‐independent molecules, in the cyclohexa‐2,5‐diene, (II). These strong synthons are further stabilized by C[triple‐bond]C—H?O=C, Cmethylene—H?O(H) and Cmethyl—H?O(H) interactions. The direct intermolecular interactions between donors and acceptors in the gem‐alkynol group, which characterize the bis(gem‐alkynol) analogues of (I) and (II), are not present in the ketone derivatives studied here. 相似文献
4.
Graldine Calvet Nicolas Blanchard Cyrille Kouklovsky Rgis Guillot 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):o365-o368
The crystal structures of 2,2‐dimethyl‐5‐nitroso‐1,3‐dioxan‐5‐yl benzoate, C13H15NO5, (I), 2,2‐dimethyl‐5‐nitroso‐1,3‐dioxan‐5‐yl 4‐chlorobenzoate, C13H14ClNO5, (II), and 5‐nitroso‐1,3‐dioxan‐5‐yl 4‐chlorobenzoate, C11H11NO5, (III), have been determined in order to gain insight into the conformational preference of α‐benzoyloxynitroso. Unfavourable 1,3‐diaxial interactions force (I) and (II) to crystallize in the 2,5 twist‐boat conformation, whereas compound (III), lacking this destabilizing interaction, crystallizes in the chair conformation. 相似文献
5.
Zhenfeng Zhang Dong Xian Jianping Li Guisheng Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(4):o191-o194
In 1‐(4‐chloroanilinomethyl)‐5‐(4‐chlorophenyl)‐1,3,5‐triazinane‐2‐thione, C16H16Cl2N4S, there are two independent molecules in the asymmetric unit which form inversion dimers via two weak N—H...S hydrogen bonds. The dimers are then linked into C(9)C(14) chains by a C—H...S hydrogen bond and a C—H...Cl contact. In 1‐(anilinomethyl)‐5‐phenyl‐1,3,5‐triazinane‐2‐thione, C16H18N4S, molecules are linked into complex sheets via a combination of N—H...S and C—H...π hydrogen bonds. 相似文献
6.
Jayanta Kumar Ray Pranab Haldar M. Canle L. J. A. Santaballa Jose Mahía 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o163-o165
The title compounds, C20H20FNO6 and C20H19Cl2NO6, respectively, may exhibit bioactivity. In these compounds, the pyrrolidine ring adopts a conformation intermediate between envelope and half‐chair. Only one of the two ethoxycarbonyl side chains is nearly planar. Centrosymmetric pairs are formed, and the crystal structure is stabilized by weak C—H⋯O hydrogen bonds and van der Waals interactions. 相似文献
7.
Masaaki Tomura Md. Akhtaruzzaman Kazuharu Suzuki Yoshiro Yamashita 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o373-o375
In the crystal structures of the title compounds, C6H2I2N2S, (I), and C12H4I2N4S2, (II), respectively, a large number of short inter‐heteroatom contacts, such as S?N, I?I and N?I, are observed. In (II), which is non‐centrosymmetric, two halves of the molecule are related by a crystallographic twofold axis. 相似文献
8.
Svitlana V. Shishkina Irina S. Konovalova Pavlo V. Trostianko Anna O. Geleverya Sergiy M. Kovalenko Natalya D. Bunyatyan 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(11):1541-1553
This study of 3‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)‐2H‐chromen‐2‐one, C17H10N2O3, 1 , and 3‐[5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl]‐2H‐chromen‐2‐one, C16H9N3O3, 2 , was performed on the assumption of the potential anticancer activity of the compounds. Three polymorphic structures for 1 and two polymorphic structures for 2 have been studied thoroughly. The strongest intermolecular interaction is stacking of the `head‐to‐head' type in all the studied crystals. The polymorphic structures of 1 differ with respect to the intermolecular interactions between stacked columns. Two of the polymorphs have a columnar or double columnar type of crystal organization, while the third polymorphic structure can be classified as columnar‐layered. The difference between the two structures of 2 is less pronounced. Both crystals can be considered as having very similar arrangements of neighbouring columns. The formation of polymorphic modifications is caused by a subtle balance of very weak intermolecular interactions and packing differences can be identified only using an analysis based on a study of the pairwise interaction energies. 相似文献
9.
N‐(2‐Bromoethyl)‐4‐piperidino‐1,8‐naphthalimide and N‐(3‐bromopropyl)‐4‐piperidino‐1,8‐naphthalimide
Tei Tagg C. John McAdam Brian H. Robinson Jim Simpson 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(7):o388-o391
N‐(2‐Bromoethyl)‐4‐piperidino‐1,8‐naphthalimide, C19H19BrN2O2, (I), and N‐(3‐bromopropyl)‐4‐piperidino‐1,8‐naphthalimide, C20H21BrN2O2, (II), are an homologous pair of 1,8‐naphthalimide derivatives. The naphthalimide units are planar and each piperidine substituent adopts a chair conformation. This study emphasizes the importance of π‐stacking interactions, often augmented by other contacts, in determining the crystal structures of 1,8‐naphthalimide derivatives. 相似文献
10.
John N. Low Justo Cobo Manuel Nogueras Adolfo Snchez Jairo Quiroga Carlos Cisneros 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o38-o39
The supramolecular structure of the title compound, C18H17ClN2O2, is determined by the intersection of two chains formed by N—H⋯O and N—H⋯N hydrogen bonds, forming a two‐dimensional sheet. 相似文献
11.
Ji‐Min Du Hui‐Yi Zeng Zhen‐Chao Dong Guo‐Cong Guo Jin‐Shun Huang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):m396-m397
The title compound, {[Cu4(C3H4NS2)4]·2H2O}n, was produced by diffusing a solution of 2‐mercaptothiazoline in tetrahydrofuran into a solution of CuCl in CH3CN at room temperature. The structure is characterized by self‐assembled one‐dimensional chains that are condensed from butterfly‐like [Cu(C3H4NS2)]4 tetrameric units via double S‐bridging at opposite ends. The Cu—Cu distances within the Cu4 butterfly cluster are in the range 2.7103 (10)–2.9764 (10) Å, while the shortest Cu?Cu intercluster distance is 3.468 (1) Å, much longer than the sum of the van der Waals radii. 相似文献
12.
Vladimir N. Nesterov Elena A. Viltchinskaia 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):616-618
The structures of the title compounds, C15H13N3O4, (I), and C16H15N3O5 [IUPAC name: ethyl 6‐amino‐5‐cyano‐2‐methyl‐4‐(3‐nitrophenyl)‐4H‐pyrano‐3‐carboxylate], (II), are very similar, with the heterocyclic rings adopting boat conformations. The pseudo‐axial m‐nitrophenyl substituents are rotated by 84.0 (1) and 98.7 (1)° in (I) and (II), respectively, with respect to the four coplanar atoms of the boat. The dihedral angles between the phenyl rings and nitro groups are 12.1 (2) and 8.4 (2)° in (I) and (II), respectively. The two compounds have similar patterns of intermolecular N—H?O and N—H?N hydrogen bonding, which link molecules into infinite tapes along b . 相似文献
13.
Paul Tongwa Tiffany L. Kinnibrugh Geetha R. Kicchaiahgari Victor N. Khrustalev Tatiana V. Timofeeva 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(4):o155-o159
The molecules of the title compounds, C16H15NOS2, (I), and C16H13Br2NOS2, (II), are E,E‐isomers and consist of an extensive conjugated system, which determines their molecular geometries. Compound (I) crystallizes in the monoclinic space group P21/c. It has one thiophene ring disordered over two positions, with a minor component contribution of 0.100 (3). Compound (II) crystallizes in the noncentrosymmetric orthorhombic space group Pca21 with two independent molecules in the unit cell. These molecules are related by a noncrystallographic pseudo‐inversion center and possess very similar geometries. The crystal packings of (I) and (II) have a topologically common structural motif, viz. stacks along the b axis, in which the molecules are bound by weak C—H...O hydrogen bonds. The noncentrosymmetric packing of (II) is governed by attractive intermolecular Br...Br and Br...N interactions, which are also responsible for the very high density of (II) (1.861 Mg m−3). 相似文献
14.
Genivaldo Júlio Perptuo Jan Janczak 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(5):o271-o273
Crystals of the title compound, C4H8N5+·C2F3O2−, are built up of singly protonated 2,4‐diamino‐6‐methyl‐1,3,5‐triazin‐1‐ium cations and trifluoroacetate anions. The CF3 group of the anion is disordered. The oppositely charged ions interact via almost linear N—H...O hydrogen bonds, forming a CF3COO−...C4H8N5+ unit. Two units related by an inversion centre interact through a pair of N—H...N hydrogen bonds, forming planar (CF3COO−...C4H8N5+...C4H8N5+·CF3COO−) aggregates that are linked by a pair of N—H...O hydrogen bonds into chains running along the c axis. 相似文献
15.
Serkan Soylu Murat Ta Hanife Saraolu Hümeyra Bat Nezihe alkan Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o702-o704
In the title compounds, C18H20N2O2, (I), and C14H11N3O4·0.5H2O, (II), respectively, the oxime groups have an E configuration. In (I), the molecules exist as polymers bound by intermolecular C—H⋯O and O—H⋯N hydrogen bonds around inversion centres. In (II), intermolecular OW—H⋯N, OW—H⋯O and O—H⋯OW interactions stabilize the molecular packing. 相似文献
16.
Wenhui Zhang Allen G. Oliver Anthony S. Serianni 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(11):o557-o560
3‐Deoxy‐3‐fluoro‐d ‐glucopyranose crystallizes from acetone to give a unit cell containing two crystallographically independent molecules. One of these molecules (at site A) is structurally homogeneous and corresponds to 3‐deoxy‐3‐fluoro‐β‐d ‐glucopyranose, C6H11FO5, (I). The second molecule (at site B) is structurally heterogeneous and corresponds to a mixture of (I) and 3‐deoxy‐3‐fluoro‐α‐d ‐glucopyranose, (II); treatment of the diffraction data using partial‐occupancy oxygen at the anomeric center gave a high‐quality packing model with an occupancy ratio of 0.84:0.16 for (II):(I) at site B. The mixture of α‐ and β‐anomers at site B appears to be accommodated in the lattice because hydrogen‐bonding partners are present to hydrogen bond to the anomeric OH group in either an axial or equatorial orientation. Cremer–Pople analysis of (I) and (II) shows the pyranosyl ring of (II) to be slightly more distorted than that of (I) [θ(I) = 3.85 (15)° and θ(II) = 6.35 (16)°], but the general direction of distortion is similar in both structures [ϕ(I) = 67 (2)° (BC1,C4) and ϕ(II) = 26.0 (15)° (C3TBC1); B = boat conformation and TB = twist‐boat conformation]. The exocyclic hydroxymethyl (–CH2OH) conformation is gg (gauche–gauche) (H5 anti to O6) in both (I) and (II). Structural comparisons of (I) and (II) to related unsubstituted, deoxy and fluorine‐substituted monosaccharides show that the gluco ring can assume a wide range of distorted chair structures in the crystalline state depending on ring substitution patterns. 相似文献
17.
Uwe Bhme Franziska Bendrath Betty Günther 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):o631-o632
In the title compound, C8H22Cl2N2Si3, the central Si atom is tetrahedrally coordinated by two Cl and two N atoms in a molecule that has crystallographically imposed C2 symmetry. Comparison is made with the isomorphous structure having titanium instead of silicon at the central position in the diazacyclopentane ring [Tinkler, Deeth, Duncalf & McCamley (1996). Chem. Commun. pp. 2623–2624]. 相似文献
18.
Frank Seela Padmaja Chittepu Yang He Henning Eickmeier Hans Reuter 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):o173-o176
In 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (6‐aza‐2′‐deoxyuridine), C8H11N3O5, (I), the conformation of the glycosylic bond is between anti and high‐anti [χ = −94.0 (3)°], whereas the derivative 2‐(2‐deoxy‐β‐d ‐erythro‐pentofuranosyl)‐N4‐(2‐methoxybenzoyl)‐1,2,4‐triazine‐3,5(2H,4H)‐dione (N3‐anisoyl‐6‐aza‐2′‐deoxyuridine), C16H17N3O7, (II), displays a high‐anti conformation [χ = −86.4 (3)°]. The furanosyl moiety in (I) adopts the S‐type sugar pucker (2T3), with P = 188.1 (2)° and τm = 40.3 (2)°, while the sugar pucker in (II) is N (3T4), with P = 36.1 (3)° and τm = 33.5 (2)°. The crystal structures of (I) and (II) are stabilized by intermolecular N—H⋯O and O—H⋯O interactions. 相似文献
19.
Deepak Chopra T. P. Mohan B. Vishalakshi T. N. Guru Row 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o540-o543
The crystal structures of the title compounds, viz. C24H14F2N2O2, (I), and C25H17FN2O2, (II), respectively, have been determined in order to unravel the role of an ordered F atom in generating stable supramolecular assemblies. On changing the substitution from fluorine to a methyl group, C—H⋯F interactions are replaced by C—H⋯π interactions, revealing the importance of such weak interactions when present alongside N—H⋯O and C—H⋯O hydrogen bonds. The dihedral angle between the planes of the 4‐fluorophenyl ring and the pyridine ring is 26.8 (1)° in (I), while that between the planes of the 4‐methylphenyl and pyridine rings is 29.5 (1)° in (II). 相似文献
20.
Hans Joachim Breunig Enno Lork Ovidiu Moldovan Ciprian I. Ra? 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):m548-m549
The structure of the title compound, alternatively called bis(μ‐tetramethyldistibinediyl)bis(tetracarbonylchromium), [Cr2Sb4(CH3)8(CO)8], consists of two Me4Sb2 bridging units between Cr(CO)4 complex fragments. The centre of the molecule is located on a special position of 2/m symmetry. This is the first characterized Sb4Cr2 heterocycle. 相似文献