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1.
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
2.
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
3.
John Nicolson Low Justo Cobo Manuel Nogueras Adolfo Snchez Braulio Insuasty Harlen Torres 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o39-o41
2,2‐Dimethyl‐5‐[3‐(4‐methylphenyl)‐2‐propenylidene]‐1,3‐dioxane‐4,6‐dione, C16H16O4, crystallizes in the triclinic space group , with two molecules in the asymmetric unit. These molecules and a centrosymmetrically related pair, linked together by weak C—H?O hydrogen bonds, form a tetramer. 5‐[3‐(4‐Chlorophenyl)‐2‐propenylidene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione, C15H13ClO4, also crystallizes in the triclinic space group , with one molecule in the asymmetric unit. Centrosymmetrically related molecules are linked together by weak C—H?O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C—H?O hydrogen bonds to form a tube which runs parallel to the a axis. 相似文献
4.
Yi‐Xun Zhang Shauntina H. Jackson Mohamed S. Rajab Frank R. Fronczek Steven F. Watkins 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o219-o221
3β‐Hydroxy‐7‐drimen‐12,11‐olide hemihydrate, C15H22O3·0.5H2O, (I), has two sesquiterpene molecules and one water molecule in the asymmetric unit. The OH groups of both molecules and both H atoms of the water molecule are involved in near‐linear intermolecular hydrogen bonds, having O⋯O distances in the range 2.632 (3)–2.791 (2) Å. 3β‐Acetoxy‐7‐drimen‐12,11‐olide, C17H24O4, (II), has its ring system in very nearly the same conformation as the two molecules of (I). 相似文献
5.
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
6.
S. Thamotharan V. Parthasarathi Ranju Gupta D. P. Jindal Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):o405-o407
The asymmetric unit of the title compound, C25H30FN3O·0.5CH3OH, contains four symmetry‐independent steroid and two methanol molecules. The conformations of the independent steroid molecules are very similar. Intermolecular O—H⋯O hydrogen bonds create two independent chains, each of which links two of the independent steroid molecules plus one methanol molecule via a co‐operative O—H⋯O—H⋯O—H pattern. Intermolecular C—H⋯O and C—H⋯F interactions are also observed. 相似文献
7.
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
8.
Tali Lavy Yana Sheynin Moshe Kapon Menahem Kaftory 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o50-o53
The crystal structures of three 1:2 inclusion compounds that consist of host molecule 2,5‐diphenylhydroquinone (C18H14O2) and the guest molecules 2‐pyridone (C5H5NO), 1,3‐diphenyl‐2‐propen‐1‐one (chalcone, C15H12O) and 1‐(4‐methoxyphenyl)‐3‐phenyl‐2‐propen‐1‐one (4′‐methoxychalcone, C16H14O2) were determined in order to study the ability of guest molecules in inclusion compounds to undergo photoreaction. All of the crystals were found to be photoresistant. The three inclusion compounds crystallize in triclinic space group . In each case, the host/guest ratio is 1:2, with the host molecules occupying crystallographic centers of symmetry and the guest molecules occupying general positions. The guest molecules in each of the inclusion compounds are linked to the host molecules by hydrogen bonds. In the inclusion compound where the guest molecule is pyridone, the host molecule is disordered so that the hydroxy groups are distributed between two different sites, with occupancies of 0.738 (3) and 0.262 (3). The pyridone molecules form dimers via N—H⋯O hydrogen bonds. 相似文献
9.
Ana Tesouro Vallina Helen Stoeckli‐Evans 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):489-490
The title compound, C24H18N4O, is a bis‐bidentate Schiff base ligand exhibiting pseudo‐C2 symmetry. The molecule is twisted about the central ether linkage and exhibits an imine E configuration. In the crystal, the molecules are linked by weak intermolecular C—H?N hydrogen bonds. 相似文献
10.
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
11.
Dubravka Matkovi‐alogovi Jasminka Popovi Zora Popovi Igor Picek
eljka Soldin 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):m39-m40
The title compound, [HgBr(C7H4NO4)(H2O)], was obtained by the reaction of an aqueous solution of mercury(II) bromide and pyridine‐2,6‐dicarboxylic acid (picolinic acid, dipicH2). The shortest bond distances to Hg are Hg—Br 2.412 (1) Å and Hg—N 2.208 (5) Å; the corresponding N—Hg—Br angle of 169.6 (1)° corresponds to a slightly distorted linear coordination. There are also four longer Hg—O interactions, three from dipicH? [2.425 (4) and 2.599 (4) Å within the asymmetric unit, and 2.837 (4) Å from a symmetry‐related molecule] and one from the bonded water molecule [2.634 (4) Å]. The effective coordination of Hg can thus be described as 2+4. The molecules are connected to form double‐layer chains parallel to the y axis by strong O—H?O hydrogen bonds between carboxylic acid groups of neighbouring molecules, and by weaker hydrogen bonds involving both H atoms of the water molecule and the O atoms of the carboxylic acid groups. 相似文献
12.
A. Subbiah Pandi D. Velmurugan S. Shanmuga Sundara Raj Hoong‐Kun Fun M. C. Bansal 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o302-o304
The title compound, C19H20O6, crystallizes in the centrosymmetric space group P21/c with one molecule in the asymmetric unit. The molecule is approximately planar and the dihedral angle between the phenyl rings is 11.0 (1)°. The H atoms of the central propenone group are trans. There is an intramolecular O—H⃛O hydrogen bond and the molecules are crosslinked by four intermolecular C—H⃛O hydrogen bonds, producing a three‐dimensional network. 相似文献
13.
Cem Cüneyt Ersanl idem Albayrak Mustafa Odabaolu Carsten Thne Ahmet Erdnmez 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o133-o135
The structure of the title compound, C18H20ClN3O5, displays the characteristic features of azobenzene derivatives. Intramolecular N—H⋯O, weak intramolecular C—H⋯O, and intermolecular O—H⋯O and C—H⋯O interactions influence the conformation of the molecules and the crystal packing. Intermolecular hydrogen bonds link the molecules into infinite chains, and the title compound adopts the keto–amine tautomeric form. The azobenzene moiety of the molecule has a trans configuration. The molecule is not planar, and the dihedral angle between the two phenyl rings is 35.6 (2)°. 相似文献
14.
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
15.
Christophe Faulmann Anthony E. Pullen 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):o338-o340
The title compound, C10H12O6S, has been obtained as dark‐yellow chunk‐shaped crystals, together with the expected thin white needles. The structures of the two phases are identical. Two independent molecules compose the asymmetric unit: one molecule is totally planar, whereas a methyl group of the second molecule points out of the plane. Each molecule participates in several intra‐ and intermolecular hydrogen bonds and short contacts. The overall structure can be regarded as parallel sheets of molecules. Within a sheet, molecules are connected to one another in an infinite network via numerous short intermolecular contacts. Sheets are connected via hydrogen bonds and short contacts, in particular involving the methyl groups. 相似文献
16.
Miroslav Bo
a Duan Valigura Ingrid Svoboda Hartmut Fuess Wolfgang Linert 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):838-839
The title compound, C19H14N5+·ClO4?·H2O, contains planar C19H14N5+ cations, perchlorate anions and water molecules. The two closest parallel cations (plane‐to‐plane distance of 3.41 Å), together with two neighbouring perchlorate anions and two water molecules, form an electrically neutral quasi‐dimeric unit. Two acidic H atoms of the cation, both H atoms of the water molecule, the N atoms of the imidazole rings and three of the four O atoms of the perchlorate anion are involved in the hydrogen‐bonding network within the dimeric unit. The remaining third acidic H atom of the imidazole rings and the water molecules complete a two‐dimensional network of hydrogen bonds, thus forming puckered layers of dimers. The angle between the planes of two neighbouring dimeric units in the same layer is 33.25 (3)°. 相似文献
17.
Vratislav Langer Miroslav Ko Dalma Gyepesov Juraj Kronek Jozef Lusto Mariana Sldkovi
ov 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(10):o602-o606
Crystal structures are reported for three isomeric compounds, namely 2‐(2‐hydroxyphenyl)‐2‐oxazoline, (I), 2‐(3‐hydroxyphenyl)‐2‐oxazoline, (II), and 2‐(4‐hydroxyphenyl)‐2‐oxazoline, (III), all C9H9NO2 [systematic names: 2‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (I), 3‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (II), and 4‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (III)]. In these compounds, the deviation from coplanarity of the oxazoline and benzene rings is dependent on the position of the hydroxy group on the benzene ring. The coplanar arrangement in (I) is stabilized by a strong intramolecular O—H⋯N hydrogen bond. Surprisingly, the 2‐oxazoline ring in molecule B of (II) adopts a 3T4 (C2TC3) conformation, while the 2‐oxazoline ring in molecule A, as well as that in (I) and (III), is nearly planar, as expected. Tetramers of molecules of (II) are formed and they are bound together via weak C—H⋯N hydrogen bonds. In (III), strong intermolecular O—H⋯N hydrogen bonds and weak intramolecular C—H⋯O hydrogen bonds lead to the formation of an infinite chain of molecules perpendicular to the b direction. This paper also reports a theoretical investigation of hydrogen bonds, based on density functional theory (DFT) employing periodic boundary conditions. 相似文献
18.
Mrcia R. Siqueira Liange de Oliveira Diehl Robert A. Burrow 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):m67-m69
In the centrosymmetric title compound, [Co2(C12H10O2P)4(C5H5N)4(H2O)2], each approximately octahedral Co atom features two trans‐coordinated pyridine molecules, one water molecule, a terminally coordinated monodentate diphenylphosphinate ligand, and two bidentate diphenylphosphinate ligands that bridge the two Co atoms across a centre of inversion to form a dimeric binuclear complex. The discrete molecules are linked by double hydrogen bonds between the terminally coordinated diphenylphosphinate ligand and the water molecule to form a continuous chain along the crystallographic b axis. 相似文献
19.
Yu‐Ling Wang 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):m522-m524
In the title compound, {[Zn(C10H8N2)(H2O)4](C6H5O4S)2·3H2O}n, the Zn atom, the bipyridine ligand and one of water molecules are located on twofold rotation axes. The Zn atom is coordinated by four O atoms from four water molecules and two N atoms from two 4,4′‐bipyridine molecules in a distorted octahedral geometry. The Zn2+ ions are linked by the 4,4′‐bipyridine molecules to form a one‐dimensional straight chain propagating along the c axis. The 4‐hydroxybenzenesulfonate counter‐ions are bridged by the solvent water molecules through hydrogen bonds to generate a two‐dimensional layer featuring large pores. In the crystal packing, the intralayer pores form one‐dimensional channels along the c axis, in which the one‐dimensional [Zn(C10H8N2)(H2O)4]2+ chains are encapsulated. Electrostatic interactions between cations and anions and extensive hydrogen bonds result in a three‐dimensional supramolecular structure. 相似文献
20.
Vratislav Langer Dalma Gyepesov Pavel Mach Eva Scholtzov Marta Saliov Andrej Boh
Boris Gpr 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o199-o202
Crystals of the title racemic compound, C11H13NO2, consist of two types of molecules (conformers); one molecule has an exocyclic OH group in an equatorial position and the other has this group in an axial position. Consequently, the hydrogen‐bond schemes for the two molecules are different. The molecules with equatorial OH groups create infinite parallel chains (formed by the same enantiomer), connected by centrosymmetric dimers of molecules (of mixed enantiomers), both with axial OH groups. Possible interconversion of the conformers and the flexibility of the molecule were studied by means of different MP2 and density functional theory (DFT) methods. The optimization of the structure by the DFT method confirmed the types of the hydrogen bonds. 相似文献