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1.
Rubn A. Toscano Emma Maldonado Alfredo Ortega Jorge Crdenas 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):846-847
The absolute configuration of the neoclerodane glycoside amarisolide, presented here as the monohydrate, C26H36O9·H2O, has been determined by association with the known configuration of the glucose moiety. Its structure was established as 2β‐(O‐β‐d ‐glucopyranosyl)neocleroda‐3,13(16),14‐trien‐15,16‐epoxy‐18,19‐olide. Extensive hydrogen bonding among the hydroxyl groups of the sugar moiety forms layers which are interconnected by water molecules. 相似文献
2.
Damon A. Parrish A. Alan Pinkerton 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(2):o80-o82
The title solvate of the steroid 17β‐estradiol (E2) with methanol and water, C18H24O2·0.67CH4O·0.33H2O, is the first E2 derivative to contain three crystallographically independent molecules in the asymmetric unit. The three steroid molecules, along with two methanol molecules and a water molecule, create a three‐dimensional hydrogen‐bonded system. Three‐sided columns are formed, with the estradiol molecules aligned lengthwise parallel to (101), and joined by solvent molecules at both hydrophilic ends. The three estradiol molecules differ slightly in their ring‐bowing angles, i.e. the angle between the mean plane of the A ring and that of the BCD ring; this angle ranges from 7.1 to 12.2°. 相似文献
3.
A. Bagaria S. Ramakumar M. Gupta V. S. Chauhan 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):o174-o176
The title compound (systematic name: 3‐benzylidene‐6‐isobutylpiperazine‐2,5‐dione), C15H18N2O2, an α,β‐dehydrophenylalanine containing diketopiperazine, crystallizes in the space group P1 with two molecules in the asymmetric unit arranged antiparallel to one another. The α,β‐dehydrophenylalanine (ΔPhe) residue in this cyclic peptide retains its planarity but deviates from the standard conformations observed in its linear analogues. Each type of molecule forms a linear chain with molecules of the same type via pairwise N—H⋯O hydrogen bonds, while weaker C—H⋯O interactions link the chains together to form a three‐dimensional network. 相似文献
4.
Jan W. Bats Uwe Parsch Joachim W. Engels 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1129-1131
Crystals of 4,2′‐anhydro‐5‐(β‐d ‐arabinofuranosyl)uracil, (I), obtained from an aqueous solution, were characterized as the dihydrate, C9H10N2O5·2H2O, (Ia). In air, these crystals slowly transform to the monohydrate, C9H10N2O5·H2O, (Ib), but remain crystalline. The solid‐state transformation proceeds with the loss of one water molecule and a rearrangement of hydrogen‐bonded layers of molecules. The furanose ring in (I) has an approximate C4′‐exo,O4′‐endo twist conformation. The central five‐membered ring is slightly puckered. The uracil group is planar within experimental uncertainty. 相似文献
5.
Raffaella Soave Riccardo Destro 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o507-o509
The asymmetric unit of the title compound, C22H31N3O4·H2O, incorporates one water molecule, which is hydrogen bonded to the 3‐oxo O atom of the indolizidinone system. The two rings of the peptidomimetic molecule are trans‐fused, with the six‐membered ring having a slightly distorted half‐chair conformation and the five‐membered ring having a perfect envelope conformation. The structure is stabilized by intermolecular O—H?O interactions between the water and adjacent peptide molecules, and by N—H?O interactions between the peptide molecules, which link the molecules into infinite chains. 相似文献
6.
L. C. R. Andrade J. A. Paixo M. J. M. de Almeida E. J. Tavares da Silva M. L. S e Melo F. M. Fernandes Roleira 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o82-o83
The title compound, alternatively called 24‐nor‐5β‐chol‐22‐ene‐3β,7α,12α‐triyl triformate, C26H38O6, has a cis junction between two of the six‐membered rings. All three of the six‐membered rings have chair conformations that are slightly flattened and the five‐membered ring has a 13β,14α‐half‐chair conformation. The 3β, 7α and 12α ring substituents are axial and the 17β group is equatorial. The 3β‐formyloxy group is involved in one weak intermolecular C—H⋯O bond, which links the molecules into dimers in a head‐to‐head fashion. 相似文献
7.
Jarmila Duskova Jiri Labsky Ivana Cisarova Tereza Skalova Jan Dohnalek Jindrich Hasek 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o563-o566
The asymmetric unit of the title compound, C11H5D16N2O2·0.33H2O, is formed by three crystallographically independent piperidin‐1‐yloxyl molecules and a molecule of water. The molecules are crosslinked by nine hydrogen bonds into layers parallel with the ac plane. The water molecule contributes to the stability of the low‐symmetry arrangement by four hydrogen bonds. 相似文献
8.
Alan Barcon Andrew P. J. Brunskill Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o140-o142
The title monohydrate, C7H10O3·H2O, aggregates as a complex hydrogen‐bonding network, in which the water molecule accepts a hydrogen bond from the carboxyl group of one molecule and donates hydrogen bonds to ketone and carboxyl Czdbnd;O functions in two additional molecules, yielding a sheet‐like structure of parallel ribbons. The keto acid adopts a chiral conformation through rotation of the carboxyl group by 62.50 (15)° relative to the plane defined by its point of attachment and the ketone C and O atoms. Two C—H⋯O close contacts exist in the structure. 相似文献
9.
Sujittra Youngme Jaturong Phatchimkun Narongsak Chaichit 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):m267-m268
In the structure of the title complex, [Cu(C2O4)(C10H9N3)(H2O)]·H2O, the CuII atom displays a square‐pyramidal geometry, being coordinated by two N atoms from the di‐2‐pyridylamine ligand, two O atoms from the oxalate group and one O atom of a water molecule. The complex molecules are linked to form a three‐dimensional supramolecular array by hydrogen‐bonding interactions between coordinated/uncoordinated water molecules and the uncoordinated oxalate O atoms of neighboring molecules. 相似文献
10.
Sabahat
zcan Engin Kendi Meral Tunbilek Hakan Gker 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):459-460
The title compound, C21H23ClN4O2·0.5H2O, contains two independent molecules in the asymmetric unit. In each molecule the piperazine ring adopts a chair conformation; the deviations of the piperazine N atoms from the best plane through the remaining four C atoms are ?0.678 (3) and 0.662 (3) Å in molecule A, and 0.687 (3) and ?0.700 (3) Å in molecule B. The molecules are linked by two hydrogen bonds of the O—H?N type involving the O atom of the water molecule of crystallization. 相似文献
11.
Carlo Andrea Mattia Alessandra Braca Nunziatina De Tommasi Raffaella Puliti 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):o644-o646
The title tetracyclic diterpenoid, 10,13,16,17‐tetrahydroxy‐9‐methyl‐15‐oxo‐20‐norkaurane‐18,10‐carbolactone hemihydrate, C20H28O6·0.5H2O, is a plant metabolite from Parinari sprucei, part of the Venezuelan Amazon flora. The asymmetric unit consists of two nearly identical molecules of the diterpenoid and one molecule of water. Some of the geometric parameters reflect steric strain in the molecule. The extended structure is characterized by hydrogen bonds and weaker hydrogen‐mediated interactions, which involve all of the hydroxy groups and propagate in sheets that coincide with the (002) family of planes. The water molecule acts as a double hydrogen‐bond donor and single acceptor and thus plays a critical role in the pattern of intermolecular interactions. 相似文献
12.
Ivan Leban Boenna Golankiewicz Joanna Zeidler Gerald Giester Joe Kobe 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o133-o135
In the title compound, C13H13N5O4·H2O (4,5′‐cyclowyosine·H2O), the cyclization forces a syn arrangement of the aglycon with respect to the sugar moiety. The ribofuranose part of the molecule displays a β‐d configuration with an envelope C1′‐endo pucker. The molecules are arranged in columns along the short a axis and are linked to water molecules through O—H?O and O—H?N hydrogen bonds. 相似文献
13.
Andrzej Gzella 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):505-507
The X‐ray crystal structure analyses of 3β‐hydroxy‐11‐oxo‐18α‐olean‐12‐en‐28‐oic acid methyl ester ethanol solvate, C31H48O4·C2H6O, (I), and 3,11‐dioxo‐18α‐olean‐12‐en‐28‐oic acid methyl ester, C31H46O4, (II), are described. These two compounds differ only in the structure of ring A. In (I), ring A has a chair conformation, while in (II), it has a twisted boat conformation. In both compounds, ring C has a slightly distorted sofa conformation, rings B, D and E are in chair conformations, and rings D and E are trans‐fused. The asymmetric unit of (I) contains one molecule of ethanol linked by hydrogen bonds with two different molecules of (I). 相似文献
14.
Elizabeth M. Kikolski Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o394-o396
The asymmetric unit of the title compound, C24H36O4, contains three molecules, all differing in their side‐chain conformations and all linked by hydrogen bonding confined entirely within a three‐molecule block. One connection is of the acid‐to‐ketone type [O⋯O = 2.7055 (19) Å and O—H⋯O = 180°] and the other involves carboxyl pairing [O⋯O = 2.6485 (18) and 2.6598 (18) Å, and O—H⋯O = 168 and 174°]. Numerous intermolecular C—H⋯O close contacts connect neighbouring molecules. 相似文献
15.
Masood Parvez Oliver E. Edwards Zdzisaw Paryzek 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):o249-o251
The structures of 3β‐acetoxy‐9α,11α‐epoxy‐5α‐lanost‐9(11)‐en‐7‐one and 3β‐acetoxy‐9β,11β‐epoxy‐5α‐lanost‐9(11)‐en‐7‐one, C32H52O4, differ in their respective substituted cyclohexanone rings but adopt similar conformations in the other three rings. In both of the crystal structures, weak intermolecular C—H⋯O interactions are present. 相似文献
16.
John N. Low Debbie Cannon Antonio Quesada Antonio Marchal Manuel Melguizo Manuel Nogueras Adolfo Snchez Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):604-607
In the title compound, 2C10H15N5O4·0.5H2O, there are two independent molecules of the pyrimidinylisoleucine in general positions and a water molecule lying on a twofold rotation axis. The bond lengths within the organic moieties demonstrate significant polarization of the electronic structure. Each of the organic molecules participates in 12 intermolecular hydrogen bonds, of O—H?O and N—H?O types, while the water molecule acts as a double donor and as a double acceptor of O—H?O hydrogen bonds. The organic components are linked by the hydrogen bonds into a single three‐dimensional framework, reinforced by the water molecules. 相似文献
17.
Lamine Hamdellou Olivier Hernandez Jean Meinnel 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o557-o560
The structures of 4‐dimethylamino‐β‐nitrostyrene (DANS), C10H12N2O2, and 4‐dimethylamino‐β‐ethyl‐β‐nitrostyrene (DAENS), C12H16N2O2, have been solved at T = 100 K. The structure solution for DANS was complicated by the presence of a static disorder, characterized by a misorientation of 17% of the molecules. The molecule of DANS is almost planar, indicating significant conjugation, with a push–pull effect through the styrene skeleton extending up to the terminal substituents and enhancing the dipole moment. As a consequence of this conjugation, the hexagonal ring displays a quinoidal character; the lengths of the C—N [1.3595 (15) Å] and C—C [1.448 (2) Å] bonds adjacent to the benzene ring are shorter than single bonds. The molecules are stacked in dimers with antiparallel dipoles. In contrast, the molecule of DAENS is not planar. The ethyl substituent pushes the nitropropene group out of the benzene plane, with a torsion angle of −21.9 (3). Nevertheless, the molecule remains conjugated, with a shortening of the same bonds as in DANS. 相似文献
18.
Eleonora Freire Sergio Baggio Juan Carlos Muoz Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o259-o262
The structures of the mono‐ and sesquihydrates of 2,6‐bis(1H‐benzimidazol‐2‐yl)pyridine (bbip) are reported. Phase (I), C19H13N5·H2O, has one water and one bbip molecule in the asymmetric unit, while phase (II), C19H13N5·1.5H2O, has three water molecules and two bbip molecules in the asymmetric unit. The compounds exhibit very similar molecular geometries but different packing organizations, which result from intricate hydrogen‐bonding schemes. 相似文献
19.
Uwe Hamann Jan Kmpen Peter Bubenitschek Henning Hopf Peter G. Jones 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o178-o181
The title 1,2‐diol derivative, C10H12O2, crystallizes with two independent but closely similar molecules in the asymmetric unit. Only two of the four OH groups are involved in classical hydrogen bonding; the molecules thereby associate to form chains parallel to the short c axis. The other two OH groups are involved in O—H⋯(C[triple‐bond]C) systems. Additionally, three of the four C[triple‐bond]C—H groups act as donors in C—H⋯O interactions. The 1,4‐diol derivative crystallizes with two independent half‐molecules of the diol (each associated with an inversion centre) and one water molecule in the asymmetric unit, C12H16O2·H2O. Both OH groups and one water H atom act as classical hydrogen‐bond donors, leading to layers parallel to the ac plane. The second water H atom is involved in a three‐centre contact to two C[triple‐bond]C bonds. One acetylenic H atom makes a very short `weak' hydrogen bond to a hydroxy O atom, and the other is part of a three‐centre system in which the acceptors are a hydroxy O atom and a C[triple‐bond]C bond. 相似文献
20.
W. Mark Barnett Russell G. Baughman Paula M. Secondo Charles J. Hermansen 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o565-o567
The crystal structures of the title compounds, alternatively called 2,2′‐(2,2′‐biimidazole‐1,1′‐diyl)diacetohydrazide monohydrate, C10H14N8O2·H2O, (I), and 3,3′‐(2,2′‐biimidazole‐1,1′‐diyl)dipropionohydrazide, C12H18N8O2, (II), respectively, have been determined. The molecules consist of half‐molecule asymmetric units related by a twofold rotation in (I) and by a center of inversion in (II). The imidazole rings of both molecules crystallize in a nearly coplanar fashion [dihedral angles of 5.91 (3) and 0.0 (1)° for (I) and (II), respectively]. Both planar hydrazinocarbonylalkyl substituents are essentially planar and assume the E orientation. 相似文献