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1.
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
2.
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
3.
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
4.
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
5.
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
6.
Jacob M. Newman Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o402-o404
The title keto acid, C20H26O4, forms carboxyl‐to‐ketone hydrogen‐bonding catemers [O?O = 2.653 (5) Å and O—H?O = 172 (5)°], linking translationally related molecules via the A‐ring ketone. The two molecules in the cell form two parallel counter‐directional chains, screw‐related in b. A total of four intermolecular C—H?O=C close contacts was found, involving both ketone functions. 相似文献
7.
Mark Davison Hugh W. Thompson Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o242-o244
The 68.5:31.5 mixture of diastereoisomers obtained in the synthesis of the title compound, C12H16O3, yielded sharply melting crystals containing the same ratio of epimers, in a disordered crystallographic arrangement. The disorder resides almost entirely in the carboxymethyl side chain, but places the two sets of carboxyl O atoms at nearly identical paired spatial positions. Neither component displays significant carboxyl disorder, and the molecules aggregate as hydrogen‐bonded carboxyl‐to‐ketone catemers [O⋯O = 2.673 (4) Å and O—H⋯O = 158°] having glide‐related components, with centrosymmetrically related pairs of chains following axes perpendicular to b. Close intermolecular C—H⋯O contacts exist for both the ketone and the carboxyl group. The energetics of the epimers and of their crystallization mode are discussed. 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.
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
10.
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
11.
Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):o638-o640
The asymmetric unit of the title compound, C9H14O3, consists of two molecules having conformations that differ by 121.7 (4)° in their rotation about the equatorial substituent bond, so that the side chain extends away from the ring in different directions in the two species. The hydrogen‐bonding mode is acid‐to‐acid dimerization. However, despite the centrosymmetric space group (P), the dimers are asymmetric, formed by pairing molecules of identical chirality but differing conformational type [O⋯O = 2.681 (2) and 2.654 (2) Å, and O—H⋯O = 175 (3) and 176 (3)°]. Two intermolecular C—H⋯O=C close contacts exist, involving the ketone group of one of the molecules. A two‐phase technique is described for slow reforming of crystals of a water‐insoluble acid by contact with an aqueous solution of its water‐soluble salt. 相似文献
12.
Oscar Donoso‐Tauda Carlos A. Escobar Ramiro Araya‐Maturana Andrs Vega 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):o631-o632
The molecule of the title compound, C19H20O2S, corresponds to a chiral sulfinyldienol with two stereogenic centres, viz. the C atom susbtituted by the hydroxy group and the sulfinyl S atom. The molecule displays a V‐shape in the solid state. The dihedral angle defined by the least‐squares planes of the aromatic rings is 72.9 (1)°. The packing pattern exhibits the following intermolecular hydrogen bonds: one O—H⋯O [H⋯O = 1.98 Å, O⋯O = 2.785 (4) Å and O—H⋯O = 166°] and two C—H⋯O [H⋯O = 2.58 and 2.60 Å, C⋯O = 3.527 (5) and 3.347 (5) Å, and C—H⋯O = 164 and 134°]. These define a chain along b. 相似文献
13.
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
14.
Veysel T. Yilmaz Canan Kazak Cumhur Kirilmis Murat Koca Frank W. Heinemann 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(7):o438-o441
The molecules of 2‐benzoyl‐1‐benzofuran, C15H10O2, (I), interact through double C—H⋯O hydrogen bonds, forming dimers that are further linked by C—H⋯O, C—H⋯π and π–π interactions, resulting in a three‐dimensional supramolecular network. The dihedral angle between the benzoyl and benzofuran fragments in (I) is 46.15 (3)°. The molecules of bis(5‐bromo‐1‐benzofuran‐2‐yl) ketone, C17H8Br2O3, (II), exhibit C2 symmetry, with the carbonyl group (C=O) lying along the twofold rotation axis, and are linked by a combination of C—H⋯O and C—H⋯π interactions and Br⋯Br contacts to form sheets. The stability of the molecular packing in 3‐mesityl‐3‐methylcyclobutyl 3‐methylnaphtho[1,2‐b]furan‐2‐yl ketone, C28H28O2, (III), arises from C—H⋯π and π–π stacking interactions. The fused naphthofuran moiety in (III) is essentially planar and makes a dihedral angle of 81.61 (3)° with the mean plane of the trimethylbenzene ring. 相似文献
15.
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
16.
Carlos E. M. Carvalho Solange M. S. V. Wardell James L. Wardell Janet M. S. Skakle John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o28-o32
Molecules of the title compounds N2‐(benzoyloxy)benzamidine, C14H12N2O2, (I), N2‐(2‐hydroxybenzoyloxy)benzamidine, C14H12N2O3, (II), and N2‐benzoyloxy‐2‐hydroxybenzamidine, C14H12N2O3, (III), all have extended chain conformations, with the aryl groups remote from one another. In (I), the molecules are linked into chains by a single N—H⋯N hydrogen bond [H⋯N = 2.15 Å, N⋯N = 3.029 (2) Å and N—H⋯N = 153°] and these chains are linked into sheets by means of aromatic π–π stacking interactions. There is one intramolecular O—H⋯O hydrogen bond in (II), and a combination of one three‐centre N—H⋯(N,O) hydrogen bond [H⋯N = 2.46 Å, H⋯O = 2.31 Å, N⋯N = 3.190 (2) Å, N⋯O = 3.146 (2) Å, N—H⋯N = 138° and N—H⋯O = 154°] and one two‐centre C—H⋯O hydrogen bond [H⋯O = 2.46 Å, C⋯O = 3.405 (2) Å and C—H⋯O = 173°] links the molecules into sheets. In (III), an intramolecular O—H⋯N hydrogen bond and two N—H⋯O hydrogen bonds [H⋯O = 2.26 and 2.10 Å, N⋯O = 2.975 (2) and 2.954 (2) Å, and N—H⋯O = 138 and 163°] link the molecules into sheets. 相似文献
17.
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
18.
Jií Ludvík Jií Urban Jan Fbry Ivana Císaov 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):o259-o262
The title structures, both C10H10N4O, are substitutional isomers. The N—N bond lengths are longer and the C=N bond lengths are shorter by ca 0.025 Å than the respective average values in the C=N—N=C group of asymmetric triazines; the assessed respective bond orders are 1.3 and 1.7. There are N—H⋯O and N—H⋯N hydrogen bonds in both structures, with 4‐amino‐3‐methyl‐6‐phenyl‐1,2,4‐triazin‐5(4H)‐one containing a rare bifurcated N—H⋯N,N hydrogen bond. The structures differ in their molecular stacking and the hydrogen‐bonding patterns. 相似文献
19.
Christopher Glidewell John N. Low Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o15-o18
2‐Amino‐5‐nitrothiazole crystallizes from solution in ethanol as a monosolvate, C3H3N3O2S·C2H6O, in which the thiazole component has a strongly polarized molecular–electronic structure. The thiazole molecules are linked into centrosymmetric dimers by paired N—H⋯N hydrogen bonds [H⋯N = 2.09 Å, N⋯N = 2.960 (6) Å and N—H⋯N = 169°], and these dimers are linked by the ethanol molecules, via a two‐centred N—H⋯O hydrogen bond [H⋯O = 1.98 Å, N⋯O = 2.838 (5) Å and N—H⋯O = 164°] and a planar asymmetric three‐centred O—H⋯(O)2 hydrogen bond [H⋯O = 2.07 and 2.53 Å, O⋯O = 2.900 (5) and 3.188 (5) Å, O—H⋯O = 169 and 136°, and O⋯H⋯O = 55°], into sheets built from alternating (8) and (38) rings. These sheets are triply interwoven. 相似文献
20.
Chung‐Der Chen Andrew P. J. Brunskill Stan S. Hall Roger A. Lalancette Hugh W. Thompson 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1148-1151
α‐Oxobenzeneacetic (phenylglyoxylic) acid, C8H6O3, adopts a transoid dicarbonyl conformation in the solid state, with the carboxyl group rotated 44.4 (1)° from the nearly planar benzoyl moiety. The heterochiral acid‐to‐ketone catemers [O?O = 2.686 (3) and H?O = 1.78 (4) Å] have a second, longer, intermolecular O—H?O contact to a carboxyl sp3 O atom [O?O = 3.274 (2) and H?O = 2.72 (4) Å], with each flat ribbon‐like chain lying in the bc plane and extending in the c direction. In α‐oxo‐2,4,6‐trimethylbenzeneacetic (mesitylglyoxylic) acid, C11H12O3, the ketone is rotated 49.1 (7)° from planarity with the aryl ring and the carboxyl group is rotated a further 31.2 (7)° from the ketone plane. The solid consists of chiral conformers of a single handedness, aggregating in hydrogen‐bonding chains whose units are related by a 31 screw axis, producing hydrogen‐bonding helices that extend in the c direction. The hydrogen bonding is of the acid‐to‐acid type [O?O = 2.709 (6) and H?O = 1.87 (5) Å] and does not formally involve the ketone; however, the ketone O atom in the acceptor molecule has a close polar contact with the same donor carboxyl group [O?O = 3.005 (6) and H?O = 2.50 (5) Å]. This secondary hydrogen bond is probably a major factor in stabilizing the observed cisoid dicarbonyl conformation. Several intermolecular C—H?O close contacts were found for the latter compound. 相似文献