共查询到20条相似文献,搜索用时 15 毫秒
1.
G. Vasuki V. Parthasarathi K. Ramamurthi D. P. Jindal S. Dubey 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o162-o163
The title compound, C27H29NO2, has the outer six‐membered ring in a sofa conformation, while the central rings are in chair conformations. The five‐membered ring adopts a slightly distorted 13β,14α‐half‐chair conformation. The cyanobenzylidene moiety has an E configuration with respect to the carbonyl group at position 17. 相似文献
2.
Marc Uerdingen Markus Schürmann Hans Preut Norbert Krause 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):e415-e415
The synthesis and crystal structure analysis via X‐ray diffraction of the title compound, C20H24O4, (I), are described. The title compound is an androstadione bearing a diene in the A and B rings [Krause & Thorand (1999). Inorg. Chim. Acta, 296 , 1–11]. The diene conjugates with the carbonyl group. Intermolecular H?O contacts (2.53 and 2.64 Å; C—H?O angles 161 and 158°) indicate hydrogen bonds. 相似文献
3.
J. I. F. Paixo J. A. R. Salvador J. A. Paixo A. Matos Beja M. Ramos Silva A. M. d'A. Rocha Gonsalves 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o72-o74
In the title compound, C21H30O3, a potential inhibitor of aromatase, all rings are fused trans. Rings A and C have chair conformations which are slightly flattened, whereas the conformation of ring B is close to a half‐chair. Ring D has a 14α‐envelope conformation. The steroid nucleus has a small twist, as shown by the C19—C10⋯C13—C18 (steroid numbering) torsion angle of −6.9 (3)°. Ab initio calculations of the equilibrium geometry of the molecule reproduce this small twist, which appears to be due to the conformation of ring B rather than to packing effects. 相似文献
4.
L. C. R. Andrade J. A. Paixo M. J. M. de Almeida R. M. L. M. Martins H. I. M. Soares G. J. R. Morais M. J. S. M. Moreno M. L. S e Melo A. S. Campos Neves 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):587-589
The title compound, C23H32O4, has a 3β configuration, with the epoxy O atom at 16α,17α. Rings A and C have slightly distorted chair conformations. Because of the presence of the C5=C6 double bond, ring B assumes an 8β,9α‐half‐chair conformation slightly distorted towards an 8β‐sofa. Ring D has a conformation close to a 14α‐envelope. The acetoxy and acetyl substituents are twisted with respect to the average molecular plane of the steroid. The conformation of the molecule is compared with that given by a quantum chemistry calculation using the RHF–AM1 (RHF = Roothaan Hartree–Fock) Hamiltonian model. Cohesion of the crystal can be attributed to van der Waals interactions and weak intermolecular C—H?O interactions, which link the molecules head‐to‐tail along [101]. 相似文献
5.
Dianne D. Ellis Anthony L. Spek 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1269-1270
The molecular structure of C11H12O4, based on a norbornene core, was established to confirm the configuration of an acetoxy side‐chain group in addition to the formation of the endo product. The acetoxy side chain lies in an axial position relative to the five‐membered fused ring. Bond distances and angles show no unusual features, with all geometric parameters lying within their expected ranges. The overall stereochemistry of the molecule was ascertained from the chiral furanone starting material. 相似文献
6.
Nevzat Karaday ükriye akmak Mustafa Odabaolu Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(5):o303-o305
The title 4,4′‐disubstituted diphenyl‐1,3‐triazines, C14H15N3, (I), C12H9ClFN3, (II), and C13H12FN3, (III), each contain a triazene group (–N=N—NH–) having an extended conformation. The dihedral angles between the two benzene rings in (I), (II) and (III) are 4.3, 3.4 and 6.5°, respectively. The molecules are almost entirely planar, with maximum deviations from the mean planes of 0.1087 (2), −0.1072 (7) and 0.1401 (3) Å, respectively. In each compound, the molecules are linked by N—H⋯N hydrogen bonds to form chains and pack similarly in the crystal structures. 相似文献
7.
Magdalena Maecka Werner Massa Elbieta Budzisz 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(10):o762-o764
The title compound, C18H14O4, forms a supramolecular structure viaπ–π stacking and weak C—H⋯O and C—H⋯π interactions. The benzopyran moiety is almost planar. The benzene ring of the phenylmethyl acetate substituent is nearly perpendicular to the fused benzene and pyran rings and also to the methyl acetate group. 相似文献
8.
S. Thamotharan V. Parthasarathi Ranju Gupta D. P. Jindal Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o161-o162
In the title compound, C23H31N3O3, the outer cyclohexane rings have chair conformations, while the central cyclohexene ring adopts a half‐chair conformation. In the solid state, intra‐ and intermolecular C—H⋯N interactions are observed. 相似文献
9.
16‐[3‐Methoxy‐4‐(2‐piperidin‐1‐ylethoxy)benzylidene]‐17‐oxoandrost‐5‐en‐3β‐yl acetate monohydrate
S. Thamotharan V. Parthasarathi Ranju Gupta Sheetal Guleria D. P. Jindal Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o727-o729
The title compound, C36H49NO5·H2O, has the outer two six‐membered rings of the steroid nucleus in chair conformations. The central ring B of the steroid nucleus is in an 8β,9α‐half‐chair conformation, while ring D of the steroid adopts a slightly distorted 13β,14α‐half‐chair conformation. The piperidine ring is in a chair conformation. The methoxybenzylidene moiety has an E configuration with respect to the carbonyl group at position 17. Intermolecular O—H?O and O—H?N hydrogen bonds link the steroid and water molecules into chains which run parallel to the b axis. 相似文献
10.
11.
Hctor Novoa de Armas Oswald M. Peeters Norbert M. Blaton Camiel J. De Ranter Jos A. Ruíz Garcia Mayra Reyes Moreno Yoanna M. Alvarez Ginarte 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e582-e583
In the title compounds, C23H33NO3 and C21H30O3, respectively, the ester linkage in ring A is equatorial. In these steroids, the six‐membered rings A and B have chair conformations, but ring C can be better described as a half‐chair. The five‐membered ring D adopts a 14α‐envelop conformation. The A/B, B/C and C/D ring junctions are trans. 相似文献
12.
R. M. A. Pinto M. Ramos Silva A. Matos Beja J. A. R. Salvador J. A. Paixo 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(5):o214-o216
In the title compound, C23H34O4, which is an intermediate in the synthesis of pregnane derivatives with a modified skeleton that show potent abortion‐inducing activity, the conformation of ring B is close to half‐chair due to the presence of both the C=C double bond and the axial 5β‐methyl group. Rings A and C have conformations close to chair, while ring D has a twisted conformation around the bridgehead C—C bond. Molecules are hydrogen bonded via the hydroxyl and acetoxy groups into infinite chains. Quantum‐mechanical ab initio Roothan Hartree–Fock calculations show that crystal packing might be responsible for the low values of the angles between rings A and B, and between ring A and rings C and D, as well as for a different steric position of the methyl ketone side chain compared to the geometry of the free molecule. 相似文献
13.
Manuela Ramos Silva Vnia M. Moreira Cludia Cardoso Ana Matos Beja Jorge A. R. Salvador 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(9):o529-o531
In the title compounds, C22H29ClO3, (I), and C21H29ClO2, (II), respectively, the B rings adopt a half‐chair conformation and the D rings adopt an envelope conformation. A twist of the steroid skeleton of both compounds is observed. There is a positional disorder of the acetoxy group of (II), with the terminal atoms disordered over two positions with near equal occupancy. Quantum‐mechanical ab initio calculations using a molecular orbital Hartree–Fock method were performed for the isolated molecules, thus allowing the distinction within the structural features of these two androstane derivatives of which characteristics are intrinsic to the molecules and which are due to packing effects. The skeletal twisting was found to be innate to the molecules, while the acetoxy disorder is due to packing effects. 相似文献
14.
Katherine A. Bussey Annie R. Cavalier Jennifer R. Connell Margaret E. Mraz Kayode D. Oshin Tomislav Pintauer Allen G. Oliver 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(7):526-533
The structures of five compounds consisting of (prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine complexed with copper in both the CuI and CuII oxidation states are presented, namely chlorido{(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ3N,N′,N′′}copper(I) 0.18‐hydrate, [CuCl(C15H17N3)]·0.18H2O, (1), catena‐poly[[copper(I)‐μ2‐(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ5N,N′,N′′:C2,C3] perchlorate acetonitrile monosolvate], {[Cu(C15H17N3)]ClO4·CH3CN}n, (2), dichlorido{(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ3N,N′,N′′}copper(II) dichloromethane monosolvate, [CuCl2(C15H17N3)]·CH2Cl2, (3), chlorido{(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ3N,N′,N′′}copper(II) perchlorate, [CuCl(C15H17N3)]ClO4, (4), and di‐μ‐chlorido‐bis({(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ3N,N′,N′′}copper(II)) bis(tetraphenylborate), [Cu2Cl2(C15H17N3)2][(C6H5)4B]2, (5). Systematic variation of the anion from a coordinating chloride to a noncoordinating perchlorate for two CuI complexes results in either a discrete molecular species, as in (1), or a one‐dimensional chain structure, as in (2). In complex (1), there are two crystallographically independent molecules in the asymmetric unit. Complex (2) consists of the CuI atom coordinated by the amine and pyridyl N atoms of one ligand and by the vinyl moiety of another unit related by the crystallographic screw axis, yielding a one‐dimensional chain parallel to the crystallographic b axis. Three complexes with CuII show that varying the anion composition from two chlorides, to a chloride and a perchlorate to a chloride and a tetraphenylborate results in discrete molecular species, as in (3) and (4), or a bridged bis‐μ‐chlorido complex, as in (5). Complex (3) shows two strongly bound Cl atoms, while complex (4) has one strongly bound Cl atom and a weaker coordination by one perchlorate O atom. The large noncoordinating tetraphenylborate anion in complex (5) results in the core‐bridged Cu2Cl2 moiety. 相似文献
15.
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
16.
Dachriyanus Amri Bakhtiar Melvyn V. Sargent Brian W. Skelton Allan H. White 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o503-o504
The isolation and structural determination of rac‐eudesm‐7(11)‐en‐4‐ol, C15H26O, from the steam distillate of the flowers of Dipterocarpus cornutus Dyer (Dipterocarpaceae) is described. The structure was determined from spectroscopic data and a single‐crystal X‐ray study. Two similar independent molecules comprise the asymmetric unit of the structure. 相似文献
17.
John A. Joule Ryan M. Hellyer David S. Larsen Sally Brooker 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):o358-o360
The asymmetric unit of the title compound, C6H6N4, comprises one and a half molecules with a C2 axis through the second molecule. Each molecule consists of two planar five‐membered rings connected by a triazole–pyrrole N—N bond with the triazole ring close to being at right angles to the pyrrole ring. The molecules are linked by C—H...N hydrogen bonds and weaker offset face‐to‐face π–π interactions. 相似文献
18.
Alexandru C. Razus Liviu Birzan Mihaela Cristea Victorita Tecuceanu Anamaria Hanganu Cristian Enache 《Journal of heterocyclic chemistry》2011,48(5):1019-1027
Pyranylium perchlorates with azulen‐1‐yl moiety in 4‐position and thiophen‐2‐yl or furan‐2‐yl in 2 and 6‐positions were obtained by the substitution of 4‐chloro corresponding salts with azulenes. The pyranylium salts are used as starting materials for the synthesis of pyridine and pyridinium salts. The products were characterized and for pyridines pKa was spectroscopically determined. Several attempts were made for pyridine complexation with metal cations as Hg2+ or Ag+. J. Heterocyclic Chem., (2011). 相似文献
19.
Marciela Scarpellini Ademir Neves Adailton J. Bortoluzzi Antnio C. Joussef 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):356-358
In the title mononuclear complex, [Cu(C5H9N3)(C10H15N5)](ClO4)2, the CuII centre is surrounded by two N‐donor ligands, which impose a square‐pyramidal environment on the metal. The new tridentate ligand [2‐(imidazol‐4‐yl)ethyl][(1‐methylimidazol‐2‐yl)methyl]amine (HISMIMA) lies in the basal plane, while the histamine ligand occupies the apical and one of the basal positions around the CuII ion. 相似文献