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1.
Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o22-o23
The title keto acid, (+)‐23,24‐dinor‐3‐oxochol‐4‐en‐22‐oic acid, C22H32O3, forms carboxyl‐to‐ketone hydrogen‐bonding catemers [O?O = 2.699 (4) Å and O—H?O = 173°], linking molecules screw‐related in b. The four molecules in the cell form two parallel counter‐directional chains, screw‐related in a. Intermolecular C—H?O=C close contacts to different neighboring molecules were found for the ketone and the acid. 相似文献
2.
Andrew P. J. Brunskill Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(5):o251-o253
The title compound, C15H22O3, derived from a naturally occurring sesquiterpenoid, has two molecules in the asymmetric unit, differing principally in the rotational conformation of the carboxyl group. Each species aggregates separately as a carboxyl‐to‐ketone hydrogen‐bonding catemer [O?O = 2.752 (4) and 2.682 (4) Å, and O—H?O = 161 (4) and 168 (4)°], producing two crystallographically independent single‐strand hydrogen‐bonding helices, with opposite end‐to‐end orientations, passing through the cell in the b direction. Three intermolecular C—H?O=C close contacts exist for the ketone. 相似文献
3.
Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o679-o681
The title compound, C8H12O3, crystallizes as acid‐to‐ketone hydrogen‐bonding catemers, in which hydrogen bonds progress from the carboxyl group of each molecule to the ketone group of a translationally related neighbor [O⋯O = 2.738 (3) Å and O—H⋯O = 153 (4)°]. Four separate hydrogen‐bonding chains proceed through the cell in centrosymmetrically related pairs along axes lying in the ab plane. Three intermolecular C—H⋯O close contacts exist involving both carboxyl O atoms. Factors contributing to the choice of hydrogen‐bonding mode are discussed. 相似文献
4.
Rodrigo Abonia Christopher Glidewell John N. Low Manuel Nogueras Jairo Quiroga 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o237-o239
Molecules of the title compound, C14H17N5O4, exhibit a highly polarized molecular–electronic structure. The molecules are linked into sheets by two N—H⋯O hydrogen bonds [H⋯O = 2.03 and 2.02 Å, N⋯O = 2.836 (2) and 2.887 (2) Å, and N—H⋯O = 153 and 168°], augmented by a single C—H⋯O hydrogen bond [H⋯O = 2.47 Å, C⋯O = 3.403 (2) Å and C—H⋯O = 166°]. Pairs of sheets, related by inversion, form bilayers with interdigitated dimethoxybenzyl substituents, weakly linked by a further C—H⋯O interaction [H⋯O = 2.50 Å, C⋯O = 3.350 (2) Å and C—H⋯O = 146°]. 相似文献
5.
Hugh W. Thompson Marie L. Cot Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(10):o727-o729
The title compound, (1R)‐4,7,7‐trimethyl‐3‐oxobicyclo[2.2.1]heptane‐2‐endo‐acetic acid, C12H18O3, like its lower homolog, forms carboxyl‐to‐ketone hydrogen‐bonding catemers (Z′ = 2) [O⋯O = 2.729 (5) and 2.707 (5) Å, and O—H⋯O = 165 and 170°] with screw‐related components. The two molecules of the asymmetric unit differ slightly in conformation and produce two counter‐aligned hydrogen‐bonding chains, both aligned with the b axis. Close intermolecular C—H⋯O=C contacts exist for the ketone group of one molecule and for both the ketone and carboxyl functions in the other. 相似文献
6.
John N. Low Justo Cobo Silvia Cruz Jairo Quiroga Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o666-o668
The title compound, C17H24O4, crystallizes with two independent molecules, both lying across twofold rotation axes in space group Pccn, in a unit cell whose dimensions closely mimic those of a tetragonal cell. Each molecule contains paired O—H⋯O hydrogen bonds [H⋯O = 1.81 and 1.83 Å, O⋯O = 2.640 (2) and 2.642 (2) Å, and O—H⋯O = 168 and 162°]. 相似文献
7.
Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o274-o276
The title keto acid crystallizes as a solvate, C21H25FO4·C2H4O2, with two molecules each of steroid and acetic acid per asymmetric unit. The former are approximately parallel, with opposite end‐to‐end orientation, and form translational carboxyl‐to‐ketone hydrogen‐bonding catemers [O⋯O = 2.679 (6) and 2.650 (5) Å, and O—H⋯O = 165 and 162°] that involve the 3‐ketone group and follow the a axis. The acetic acid molecules are paired by hydrogen bonding, and neither they nor the F atom nor the 11‐ketone group play any overt role in the hydrogen‐bonding scheme of the steroid. Intermolecular C—H⋯O=C close contacts involving three different neighboring molecules exist to the 11‐ketone group, the steroidal carboxyl group and one of the acetic acid molecules. 相似文献
8.
Andrew P. J. Brunskill Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1075-1078
The anhydrous form, (I), of the title compound, (?)‐2‐(1,2,3,4,4a,7‐hexahydro‐4a,8‐dimethyl‐1,7‐dioxo‐2‐naphthyl)propionic acid, C15H18O4, derived from a naturally occurring sesquiterpenoid, has two molecules in the asymmetric unit, (I) and (I′), differing in the conformations of the saturated ring and the carboxyl group. The compound aggregates as carboxyl‐to‐ketone hydrogen‐bonding catemers [O?O = 2.776 (3) and 2.775 (3) Å]. Two crystallographically independent sets of single‐strand hydrogen‐bonding helices with opposite end‐to‐end orientation pass through the cell in the b direction, one consisting exclusively of molecules of (I) and the other entirely of (I′). Three C—H?O=C close contacts are found in (I). The monohydrate, C15H18O4·H2O, (II), with two molecules of (I) plus two water molecules in its asymmetric unit, forms a complex three‐dimensional hydrogen‐bonding network including acid‐to‐water, water‐to‐acid, water‐to‐ketone, water‐to‐water and acid‐to‐acid hydrogen bonds, plus three C—H?O=C close contacts. In both (I) and (II), only the ketone remote from the acid is involved in hydrogen bonding. 相似文献
9.
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
10.
Mark Davison Elizabeth M. Kikolski Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):o449-o451
In the title compound, C10H16O3, the two molecules of the asymmetric unit form acid‐to‐ketone hydrogen‐bonded chains. The two species differ only very slightly and are related by a pseudo‐center, so that the apparent translational relationship among the units of the hydrogen‐bonded chain is actually a pseudo‐translation, with the molecules alternating in type. Two counterdirectional pairs of chains proceed through each cell [O⋯O = 2.743 (2) and 2.683 (2) Å, and O—H⋯O = 171 (3) and 157 (3)°]. Three intermolecular C—H⋯O close contacts were found, involving all three O atoms of one of the molecules. 相似文献
11.
Lian Ee Khoo Yiqun Zhang Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):e350-e351
The title compound, C17H13NO4, exists as a planar molecule; adjacent molecules are linked by electrostatic C—H?O [C?O = 3.318 (4) and 3.455 (4) Å] interactions into a linear chain. 相似文献
12.
Jacob M. Newman Markos M. Papadakis Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):m89-m91
The title compound, [Fe(C6H5O2)(C7H7O)], adopts a conformation involving partial staggering of its rings and aggregates in the solid as acid‐to‐ketone hydrogen‐bonding dimers [O?O = 2.720 (4) Å and O—H?O = 164°] having centrosymmetrically related components. Close intermolecular C—H?O contacts were found to both carboxyl O atoms. 相似文献
13.
Jacob M. Newman Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o693-o696
Both title compounds, C9H14O3, display carboxyl‐dimer hydrogen‐bonding patterns. The 4‐acetyl isomer adopts a chiral conformation with negligible disordering of the methyl and carboxyl groups and forms centrosymmetric dimers across the b and c edges of the chosen cell [O?O = 2.667 (3) Å and O—H?O = 175°]. Intermolecular C—H?O close contacts were found for both carbonyl groups. In the 2‐acetyl isomer, there is no intramolecular interaction between the carboxyl and acetyl groups and the hydrogen bonding involves centrosymmetric carboxyl dimerization across the ab and ac faces of the chosen cell [O?O = 2.668 (2) Å and O—H?O = 173°]. The carboxyl group is negligibly disordered, but significant rotational disordering was found for the acetyl methyl group. An intermolecular C—H?O close contact was found involving the ketone group. 相似文献
14.
Markos M. Papadakis Jorge A. Pavon Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):o167-o170
The two δ‐keto carboxylic acids of the title, both C10H14O3, are epimeric at the site of carboxyl attachment. The endo (3α) epimer, (I), has its keto‐acid ring in a boat conformation, with the tilt of the carboxyl group creating conformational chirality. The molecules form hydrogen bonds by centrosymmetric pairing of carboxyl groups across the corners of the chosen cell [O⃛O = 2.671 (2) Å and O—H⃛O = 179 (2)°]. Two close intermolecular C—H⃛O contacts exist for the ketone. The exo (3β) epimer exists in the closed ring–chain tautomeric form as the lactol, 8‐hydroxy‐9‐oxatricyclo[5.3.1.03,8]undecan‐10‐one, (II). The molecules have conformational chirality, and the hydrogen‐bonding scheme involves intermolecular hydroxyl‐to‐carbonyl chains of molecules screw‐related in b [O⃛O = 2.741 (2) Å and O—H⃛O = 177 (2)°]. 相似文献
15.
Delphine Firley Bernard Fraisse Fatima Zouhiri Anne Spasojevi‐de Bir Didier Desmaële Jean D'Angelo Nour Eddine Ghermani 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):o154-o157
Both 7‐carboxylato‐8‐hydroxy‐2‐methylquinolinium monohydrate, C11H9NO3·H2O, (I), and 7‐carboxy‐8‐hydroxy‐2‐methylquinolinium chloride monohydrate, C11H10NO3+·Cl−·H2O, (II), crystallize in the centrosymmetric P space group. Both compounds display an intramolecular O—H⋯O hydrogen bond involving the hydroxy group; this hydrogen bond is stronger in (I) due to its zwitterionic character [O⋯O = 2.4449 (11) Å in (I) and 2.5881 (12) Å in (II)]. In both crystal structures, the HN+ group participates in the stabilization of the structure via intermolecular hydrogen bonds with water molecules [N⋯O = 2.7450 (12) Å in (I) and 2.8025 (14) Å in (II)]. In compound (II), a hydrogen‐bond network connects the Cl− anion to the carboxylic acid group [Cl⋯O = 2.9641 (11) Å] and to two water molecules [Cl⋯O = 3.1485 (10) and 3.2744 (10) Å]. 相似文献
16.
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
17.
Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o580-o582
In the title compound, C15H24O3, derived from a naturally occurring sesquiterpenoid, the asymmetric unit consists of two molecules differing by 167.4 (8)° in the rotational conformation of the carboxyl group. Each molecule aggregates separately with its own type as carboxyl‐to‐ketone hydrogen‐bonding catemers [O⋯O = 2.715 (6) and 2.772 (6) Å, and O—H⋯O = 169 and 168°]. This generates two crystallographically independent single‐strand hydrogen‐bonding helices passing through the cell in the b direction, with opposite end‐to‐end orientations. One intermolecular C—H⋯O=C close contact exists for the carboxyl group of one of the molecules. The structure is isostructural with that of a closely related unsaturated keto acid reported previously. 相似文献
18.
Christopher Glidewell John N. Low Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o120-o124
Molecules of 2‐(2‐nitrophenylaminocarbonyl)benzoic acid, C14H10N2O5, are linked into centrosymmetric R(8) dimers by a single O—H⋯O hydrogen bond [H⋯O = 1.78 Å, O⋯O = 2.623 (2) Å and O—H⋯O = 178°] and these dimers are linked into sheets by a single aromatic π–π stacking interaction. The isomeric compound 2‐(4‐nitrophenylaminocarbonyl)benzoic acid crystallizes in two polymorphic forms. In the orthorhombic form (space group P212121 with Z′ = 1, crystallized from ethanol), the molecules are linked into sheets of R(22) rings by a combination of one N—H⋯O hydrogen bond [H⋯O = 1.96 Å, N⋯O = 2.833 (3) Å and N—H⋯O = 171°] and one O—H⋯O hydrogen bond [H⋯O = 1.78 Å, O⋯O = 2.614 (3) Å and O—H⋯O = 173°]. In the monoclinic form (space group P21/n with Z′ = 2, crystallized from acetone), the molecules are linked by a combination of two N—H⋯O hydrogen bonds [H⋯O = 2.09 and 2.16 Å, N⋯O = 2.873 (4) and 2.902 (3) Å, and N—H⋯O = 147 and 141°] and two O—H⋯O hydrogen bonds [H⋯O = 1.84 and 1.83 Å, O⋯O = 2.664 (3) and 2.666 (3) Å, and O—H⋯O = 166 and 174°] into sheets of some complexity. These sheets are linked into a three‐dimensional framework by a single C—H⋯O hydrogen bond [H⋯O = 2.45 Å, C⋯O = 3.355 (4) Å and C—H⋯O = 160°]. 相似文献
19.
Dun‐Ru Zhu Yan Xu Yong‐Jiang Liu You Song Yong Zhang Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):242-243
In the title compound, 4‐(4H‐1,2,4‐triazol‐4‐yliminomethyl)phenol hemihydrate, C9H8N4O·0.5H2O or (I)·0.5H2O, molecules of (I) are arranged as layers running along the b axis through intermolecular O—H?N and C—H?O hydrogen bonds. These layers are stabilized by hydrogen‐bonded water molecules to form three‐dimensional networks. 相似文献
20.
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