共查询到20条相似文献,搜索用时 15 毫秒
1.
C. Foces‐Foces N. Jagerovic J. Elguero 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):215-218
The structures of 1‐methyl‐3‐nitropyrazole and 1‐methyl‐4‐nitropyrazole, C4H5N3O2, have been determined. The 3‐nitro derivative has crystallographic m‐symmetry while the 4‐nitro compound has no imposed symmetry. The significant differences in bond distances and angles between the structures are ascribable to the electron‐withdrawing effects of the nitro group attached to C3 or C4, respectively. In both structures, the molecules are organized into layers by an extensive network of C—H?O or C—H?N hydrogen interactions. Within a layer, the molecules are arranged in a similar way, although differences of up to 0.3 Å in the analogous H?O or H?N intermolecular distances are observed. The cohesion of the layers is due to van der Waals and C—H?O contacts. 相似文献
2.
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
3.
Nagarajan Vembu Maruthai Nallu Semih Durmus Matthew Panzner Jered Garrison Wiley J. Youngs 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o248-o251
The structures of the title compounds, C12H8N2O7S and C12H8ClNO5S, contain weak C—H⋯O interactions creating layers of molecules which, taking the conformation of the molecules into account, are arranged in an ABAB sequence. Both structures can be designated, therefore, as ordered racemates of rotameric species. 相似文献
4.
James L. Wardell John Nicolson Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):679-681
In the title compound, (4‐O2NC6H4)2S2 or C12H8N2O4S2, the molecules lie across twofold rotation axes. A single type of C—H?O hydrogen bond, with C?O = 3.394 (3) Å and C—H?O = 158°, links the molecules into continuous two‐dimensional sheets built from a single type of R44(44) ring. These sheets are linked by aromatic π?π stacking interactions to form a continuous three‐dimensional framework. 相似文献
5.
Urmila H. Patel Chaitanya G. Dave Mukesh M. Jotani Hetal C. Shah 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o697-o699
The title compound, C20H16N2O, has two molecules in the asymmetric unit and the crystal structure shows that the central pyridine ring of each molecule has a flat boat conformation. The terminal C atom in one of the molecules is disordered over two positions, with relative occupancies of 0.594 (14) and 0.398 (14). Intermolecular C—H?N and C—H?π interactions and π–π stacking, along with intramolecular C—H?N and C—H?π interactions, help to stabilize the structure. 相似文献
6.
A. R. Choudhury K. Nagarajan T. N. Guru Row 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o219-o222
The crystal and molecular structures of the three 4‐ketotetrahydroindoles 2‐(4‐chlorophenyl)‐1‐(4‐fluorophenyl)‐6,6‐dimethyl‐4,5,6,7‐tetrahydro‐1H‐indol‐4‐one (C22H19ClFNO), (I), 1‐(4‐fluorophenyl)‐2‐(4‐methoxyphenyl)‐6,6‐dimethyl‐4,5,6,7‐tetrahydro‐1H‐indol‐4‐one (C23H22FNO2), (II), and 6,6‐dimethyl‐1,2‐diphenyl‐4,5,6,7‐tetrahydro‐1H‐indol‐4‐one (C22H21NO), (III), have been determined via single‐crystal X‐ray diffraction in order to study the intermolecular interactions therein. All three structures are stabilized via intermolecular C—H⋯O and C—H⋯π interactions, generating different molecular motifs. 相似文献
7.
A. R Choudhury K. Nagarajan T. N. Guru Row 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o644-o647
The crystal structures of 1‐(4‐fluorophenyl)‐2‐phenyl‐4,5,6,7‐tetrahydro‐1H‐indole, C20H18FN, and 1‐(4‐fluorophenyl)‐6,6‐dimethyl‐2‐phenyl‐4,5,6,7‐tetrahydro‐1H‐indole, C22H22FN, have been determined in order to study the role of `organic fluorine' in crystal engineering. These molecules pack in the crystal structure via different types of molecular motifs utilizing weak C—H⋯F and C—H⋯π interactions. 相似文献
8.
Xiu‐Li You Cheng‐Rong Lu Yong Zhang De‐Chun Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o693-o695
Molecular packing analyses were carried out on 15 crystal data sets of chloro‐substituted Schiff bases, including that of the title compound, C15H15ClN2. C—H⋯π and π–π interactions play a major role in the molecular self‐assembly in the crystal. The former interactions favor molecules assembling into a screw, with a non‐centrosymmetric crystal structure. When the molecular dipole is small, π–π interactions favor a parallel, but not usually antiparallel, mode of packing. Weak C—H⋯X hydrogen bonds (X = Cl or Br) and X⋯X interactions seem to be a secondary driving force in packing. The title molecule takes the trans form and the two benzene rings are twisted around the central linkage in opposite directions. In the crystal structure, molecules interact through C—H⋯π and π–π interactions, forming a `dimer' and further forming double chains along [001]. The double chains are extended along [10] through C—H⋯Cl hydrogen bonds, forming double layers in (010). In the third direction, there are only ordinary, weaker, van der Waals interactions, which explains the crystal habit (i.e. thin plate). 相似文献
9.
John N. Low Justo Cobo Manuel Nogueras Adolfo Snchez Harlen Torres Braulio Insuasty 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(5):o298-o300
The supramolecular structure of the title compound, C19H15N3, is defined by π–π‐stacking and C—H?π interactions. There are no conventional hydrogen bonds in the structure. 相似文献
10.
Debbie Cannon Christopher Glidewell John N. Low James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1267-1268
In the title compound, C12H8N2O4S2, the molecules lie across twofold rotation axes in the space group C2/c. There are no intermolecular C—H?O hydrogen bonds, but the molecules are linked into chains along [001] by aromatic π?π stacking interactions. 相似文献
11.
Elizabeth J. MacLean John N. Low Antonio Quesada Manuel Melguizo Manuel Nogueras Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o442-o444
In the title compound, C14H15N5O2, the intramolecular dimensions are consistent with a highly polarized electronic structure. The molecules are linked into chains by a combination of N—H?N, N—H?O and N—H?π(arene) hydrogen bonds, and the chains are linked in pairs by aromatic π–π‐stacking interactions 相似文献
12.
Simon J. Garden Fernando R. da Cunha Christopher Glidewell John N. Low Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o12-o14
In 2‐hydroxy‐3‐iodo‐5‐nitrobenzaldehyde, C7H4INO4, the molecules are linked into sheets by a combination of C—H⋯O hydrogen bonds and two‐centre iodo–nitro interactions, and these sheets are linked by aromatic π–π stacking interactions. Molecules of 2,4‐diiodo‐6‐nitroanisole, C7H5I2NO3, are disordered, with the nitro group and one of the I substituents each occupying common sets of sites with 0.5 occupancy. The molecules are linked into isolated centrosymmetric dimeric units by a single iodo–nitro interaction. 相似文献
13.
James L. Wardell Solange M. S. V. Wardell Janet M. S. Skakle John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o428-o430
Molecules of the title compound, C13H9IN2O2, are linked into [010] chains by a single C—H?O hydrogen bond and these chains are linked into (100) sheets by two independent aromatic π–π‐stacking interactions, each involving one of the two substituted arene rings. 相似文献
14.
K. Manoj S. Devaraj R. G. Gonnade M. M. Bhadbhade M. S. Shashidhar 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(11):o628-o630
The centrosymmetric O—H⋯O‐bonded head‐to‐head dimers of the title compound, C21H22O6, are linked together via bifurcated C—H⋯O interactions along the a axis and via favourable C—H⋯π interactions along the b axis in the crystal structure. 相似文献
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19.
Christopher Glidewell John N. Low Justo Cobo Manuel Nogueras Adolfo Snchez Emerson Rengifo Rodrigo Abonia 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):o314-o317
In the title compound, C20H22N6, the molecules are linked into a chain of rings by N—H?N [H?N 2.16 Å, N?N 2.950 (3) Å and N—H?N 149°] and C—H?N [H?N 2.55 Å, C?N 3.481 (3) Å and C—H?N 165°] hydrogen bonds, and these chains are linked into sheets by means of C—H?π(pyrazole) interactions. 相似文献
20.
Comparison of halogen bonding and van der Waals and π–π interactions in 4,5‐dibromo‐2‐hexyloxyphenol
Fabio D. Cukiernik Florencia Cecchi Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(5):o233-o236
The title compound, C12H16BrO2, is an interesting case of a simple organic molecule making use of five different types of intra‐ and intermolecular interactions (viz. conventional and nonconventional hydrogen bonds, and π–π, Br...Br and Br...O contacts), all of them relevant in the molecular and crystal structure geometry. The molecules are strictly planar, with an intramolecular O—H...O hydrogen bond, and associate into two‐dimensional structures parallel to (01) through two different types of halogen bonding. The planar structures, in turn, stack parallel to each other interlinked by C—H...π and π–π contacts. Also discussed are the relevant structural features leading to the rather low melting point of the compound. 相似文献