共查询到20条相似文献,搜索用时 78 毫秒
1.
Russell G. Baughman Kenneth L. Martin Rajendra K. Singh James O. Stoffer 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o103-o106
In 2,4‐dihydroxybenzaldehyde 2,4‐dinitrophenylhydrazone N,N‐dimethylformamide solvate {or 4‐[(2,4‐dinitrophenyl)hydrazonomethyl]benzene‐1,3‐diol N,N‐dimethylformamide solvate}, C13H10N4O6·C3H7NO, (X), 2,4‐dihydroxyacetophenone 2,4‐dinitrophenylhydrazone N,N‐dimethylformamide solvate (or 4‐{1‐[(2,4‐dinitrophenyl)hydrazono]ethyl}benzene‐1,3‐diol N,N‐dimethylformamide solvate), C14H12N4O6·C3H7NO, (XI), and 2,4‐dihydroxybenzophenone 2,4‐dinitrophenylhydrazone N,N‐dimethylacetamide solvate (or 4‐{[(2,4‐dinitrophenyl)hydrazono]phenylmethyl}benzene‐1,3‐diol N,N‐dimethylacetamide solvate), C19H14N4O6·C4H9NO, (XII), the molecules all lack a center of symmetry, crystallize in centrosymmetric space groups and have been observed to exhibit non‐linear optical activity. In each case, the hydrazone skeleton is fairly planar, facilitated by the presence of two intramolecular hydrogen bonds and some partial N—N double‐bond character. Each molecule is hydrogen bonded to one solvent molecule. 相似文献
2.
Adrin Turjanski Zulema Dbora Chaia Fabio Doctorovich Dario Estrin Ruth Rosenstein Oscar E. Piro 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):682-683
The title compound, N‐[2‐(5‐methoxy‐1‐nitroso‐1H‐indol‐3‐yl)ethyl]acetamide, C13H15N3O3, an N‐nitroso derivative of melatonin, crystallizes in the monoclinic C2/c space group. The molecules are arranged in such a way that the aromatic rings are in a planar conformation, with the alkylamide side chains in a different plane, at a dihedral angle of 108.60 (6)°. The alkylamide chains are interconnected by hydrogen bonds, constituting an infinite array. 相似文献
3.
Vladimir N. Nesterov Elena A. Viltchinskaia 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):616-618
The structures of the title compounds, C15H13N3O4, (I), and C16H15N3O5 [IUPAC name: ethyl 6‐amino‐5‐cyano‐2‐methyl‐4‐(3‐nitrophenyl)‐4H‐pyrano‐3‐carboxylate], (II), are very similar, with the heterocyclic rings adopting boat conformations. The pseudo‐axial m‐nitrophenyl substituents are rotated by 84.0 (1) and 98.7 (1)° in (I) and (II), respectively, with respect to the four coplanar atoms of the boat. The dihedral angles between the phenyl rings and nitro groups are 12.1 (2) and 8.4 (2)° in (I) and (II), respectively. The two compounds have similar patterns of intermolecular N—H?O and N—H?N hydrogen bonding, which link molecules into infinite tapes along b . 相似文献
4.
Xinjiang Huang Genevieve H. Kuhn Vladimir N. Nesterov Boris B. Averkiev Benjamin Penn Mikhail Yu. Antipin Tatiana V. Timofeeva 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(10):o624-o628
Syntheses and X‐ray structural investigations have been carried out for (E)‐(4‐hydroxyphenyl)(4‐nitrophenyl)diazene, C12H9N3O3, (Ia), (E)‐(4‐methoxyphenyl)(4‐nitrophenyl)diazene, C13H11N3O3, (IIIa), and (E)‐[4‐(6‐bromohexyloxy)phenyl](4‐cyanophenyl)diazene, C19H20BrN3O, (IIIc). In all of these compounds, the molecules are almost planar and the azobenzene core has a trans geometry. Compound (Ia) contains four and compound (IIIc) contains two independent molecules in the asymmetric unit, both in space group P (No. 2). In compound (Ia), the independent molecules are almost identical, whereas in crystal (IIIc), the two independent molecules differ significantly due to different conformations of the alkyl tails. In the crystals of (Ia) and (IIIa), the molecules are arranged in almost planar sheets. In the crystal of (IIIc), the molecules are packed with a marked separation of the azobenzene cores and alkyl tails, which is common for the solid crystalline precursors of mesogens. 相似文献
5.
Jrg Schrder Herbert Wenzel Hans‐Georg Stammler Anja Stammler Beate Neumann Harald Tschesche 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):593-596
The title compounds, (2S)‐N‐[5‐(4‐chlorophenyl)‐2,3‐dihydro‐6H‐1,3,4‐thiadiazin‐2‐ylidene]‐2‐[(phenylsulfonyl)amino]propanamide, C18H17ClN4O3S2, (I), (2R)‐N‐[5‐(4‐fluorophenyl)‐6H‐1,3,4‐thiadiazin‐2‐yl]‐2‐[(phenylsulfonyl)amino]propanamide, C18H17FN4O3S2, (II), and (2S)‐N‐[5‐(5‐chloro‐2‐thienyl)‐6H‐1,3,4‐thiadiazin‐2‐yl]‐2‐[(phenylsulfonyl)amino]propanamide, C16H15ClN4O3S3, (III), are potent inhibitors of matrix metalloproteinases. In all three compounds, the thiadiazine ring adopts a screw‐boat conformation. The molecules of compound (I) show a short intramolecular NAla—H?Nexo hydrogen bond [N?N 2.661 (3) Å] and are linked into a chain along the c axis by Nendo—H?Sendo and Nendo—H?OAla hydrogen bonds [N?S 3.236 (3) and N?O 3.375 (3) Å] between neighbouring molecules. In compound (II), the molecules are connected antiparallel into a chain along the a axis by Nexo—H?OAla and NAla—H?Nendo hydrogen bonds [N?O 2.907 (6) and N?N 2.911 (6) Å]. The molecules of compound (III) are dimerized antiparallel through Nexo—H?Nendo hydrogen bonds [N?N 2.956 (7) and 2.983 (7) Å]. The different hydrogen‐bonding patterns can be explained by an amido–imino tautomerism (prototropic shift) shown by different bond lengths within the 6H‐1,3,4‐thiadiazine moiety. 相似文献
6.
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
7.
Vladimir N. Nesterov David J. Wiedenfeld Svitlana V. Nesterova Lucas F. Hastings 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):o705-o708
The syntheses, X‐ray structural investigations and calculations of the conformational preferences of the carbonyl substituent with respect to the pyran ring have been carried out for the two title compounds, viz. C15H14N2O2, (II), and C20H16N2O2·C2H3N, (III), respectively. In both molecules, the heterocyclic ring adopts a flattened boat conformation. In (II), the carbonyl group and a double bond of the heterocyclic ring are syn, but in (III) they are anti. The carbonyl group forms a short contact with a methyl group H atom in (II). The dihedral angles between the pseudo‐axial phenyl substituent and the flat part of the pyran ring are 92.7 (1) and 93.2 (1)° in (II) and (III), respectively. In the crystal structure of (II), intermolecular N—H⋯N and N—H⋯O hydrogen bonds link the molecules into a sheet along the (103) plane, while in (III), they link the molecules into ribbons along the a axis. 相似文献
8.
Christopher Glidewell John N. Low Manuel Melguizo Antonio Quesada 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(1):o14-o18
In 2‐amino‐4,6‐dimethoxy‐5‐nitropyrimidine, C6H8N4O4, the molecules are linked by one N—H⋯N and one N—H⋯O hydrogen bond to form sheets built from alternating R(8) and R(32) rings. In isomeric 4‐amino‐2,6‐dimethoxy‐5‐nitropyrimidine, C6H8N4O4, which crystallizes with Z′ = 2 in P, the two independent molecules are linked into a dimer by two independent N—H⋯N hydrogen bonds. These dimers are linked into sheets by a combination of two‐centre C—H⋯O and three‐centre C—H⋯(O)2 hydrogen bonds, and the sheets are further linked by two independent aromatic π–π‐stacking interactions to form a three‐dimensional structure. 相似文献
9.
Daniel E. Lynch Ian McClenaghan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o1-o5
The crystal structures of four trifluoromethylnitrobenzene analogues (CF3)C6H3(NO2)[C4H8N2]R (where C4H8N2 is piperazinyl and R is ethyl carboxylate, CO2C2H5, or phenyl, C6H5), have been determined, and their conformations and packing arrangements are compared. The four compounds are ethyl 4‐[4‐nitro‐2‐(trifluoromethyl)phenyl]piperazine‐1‐carboxylate, (I), and ethyl 4‐[2‐nitro‐4‐(trifluoromethyl)phenyl]piperazine‐1‐carboxylate, (II), both C14H16F3N3O4, and 1‐[4‐nitro‐2‐(trifluoromethyl)phenyl]‐4‐phenylpiperazine, (III), and 1‐[2‐nitro‐4‐(trifluoromethyl)phenyl]‐4‐phenylpiperazine, (IV), both C17H16F3N3O2. All molecules adopt a rod‐like conformation, while the asymmetric units of (II) and (IV) contain two unique molecules that pack as monodirectional pairs. All molecules pack with C—H⋯O/F close contacts to all but one of the O atoms and to five of the 18 F atoms. 相似文献
10.
Enrique Espinosa Michel Meyer David Berard Roger Guilard 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):m119-m121
The crystal structure of the title copper(II) complex, [Cu(C18H36N8O4)]SO4·4.5H2O, formed with the tetraamide cyclam derivative 2‐(4,8,11‐triscarbamoylmethyl‐1,4,8,11‐tetraazacyclotetradec‐1‐yl)acetamide (TETAM), is described. The macrocycle lies on an inversion centre occupied by the hexacoordinated Cu atom. The four macrocyclic tertiary amines form the equatorial plane of an axially Jahn–Teller elongated octahedron. Two O atoms belonging to two diagonally opposite amide groups occupy the apical positions, giving rise to a trans‐III stereochemistry, while both the remaining pendant side arms extend outwards from the macrocyclic cavity and are engaged in hydrogen bonds with sulfate anions and co‐crystallized water molecules. 相似文献
11.
John Nicolson Low Justo Cobo Braulio Insuasty Henry Insuasty Manuel Nogueras Adolfo Snchez 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o103-o105
In both title compounds, i.e. 3‐methyl‐1,5‐diphenyl‐1,6,7,8‐tetrahydropyrazolo[3,4‐b][1,4]diazepine, C19H18N4, (I), and 5‐(4‐chlorophenyl)‐3‐methyl‐1‐phenyl‐1,6,7,8‐tetrahydropyrazolo[3,4‐b][1,4]diazepine, C19H17ClN4, (II), an N—H?N hydrogen bond links six molecules to form an R(30) ring. Compound (I) crystallizes in the R space group and (II) crystallizes in P with three molecules in the asymmetric unit. The molecule of (I) contains a disordered seven‐membered ring. 相似文献
12.
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(8):o527-o530
In the title compounds, C12H12N2O2, (I), and C17H14N2O2, (II), respectively, the indole rings are planar and the vinyl groups lie out of the indole planes, making dihedral angles of 33.48 (5) and 41.31 (8)°, respectively. In (II), the dihedral angle between the phenyl and indole ring planes is 32.06 (6)°. In both molecules, the double bond connecting the methylnitrovinyl group and the indole nucleus adopts an E configuration. Notwithstanding the differences in space group [C2/c for (I) and P212121 for (II)], the mode of packing of compounds (I) and (II) is determined by similar intermolecular N—H⋯O hydrogen‐bonding interactions, forming chains that run parallel to [101] in (I) and [001] in (II). 相似文献
13.
Manfredo Hrner Leandro Bresolin Jairo Bordinhao Edmund Hartmann Joachim Strhle 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(8):o426-o427
The structure of the title compound, C12H9N5O4, reveals an almost planar molecule (r.m.s. deviation = 0.061 Å), in which the interplanar angle between the phenyl rings is 5.7 (1)° and the largest interplanar angle is that between the phenyl ring and the nitro group of one of the 4‐nitrophenyl substituents [8.8 (3)°]. The observed molecular conformation suggests a delocalization of π‐electrons extended over the diazoamine group and the terminal aryl substituents. Intermolecular N—H⃛O interactions between the twofold screw‐related molecules give rise to helical chains along the [010] direction. Intermolecular C—H⃛O interactions then generate sheets of molecules in the (10) plane, and these sheets are held together by N⃛C and O⃛O π–π interactions. 相似文献
14.
Hiroyuki Hosomi Shigeru Ohba Yoshikatsu Ito 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e147-e148
In the two title compounds, N‐methylcarbazole–3,5‐dinitrobenzonitrile (1/1), C13H11N·C7H3N3O4, (I), and N‐ethylcarbazole–3,5‐dinitrobenzonitrile (1/1), C14H13N·C7H3N3O4, (II), the donor and acceptor molecules are stacked alternately to form one‐dimensional columns. In (I), the N‐methyl group of the donor is nearly eclipsed with respect to one of the nitro groups of the neighboring acceptor in a column, whereas the N‐ethyl group is anti with respect to the cyano group of the neighboring acceptor in (II). 相似文献
15.
Sergiy V. Rosokha Jian Jiang Lu Sergey M. Dibrov Jay K. Kochi 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(8):o464-o466
The title compound, C6H2N6O10·2C2H4Cl2, forms layered stacks of pentanitroaniline molecules, which possess twofold symmetry. The voids between these stacks are occupied by dichloroethane molecules, which reside near a 2/m symmetry element and display pseudo‐inversion symmetry. The C atoms in one of the two solvent molecules are threefold disordered. In the pentanitroaniline molecule, considerable distortion of the benzenoid ring, coupled with the short C—N(H2) bond and out‐of‐plane NO2 twistings, point to significant intramolecular `push–pull' charge transfer at the amino‐ and nitro‐substituted (ortho and para) positions, as theoretically quantified by natural bond orbital analysis of the π‐electron density. 相似文献
16.
Christopher Glidewell John N. Low Susan A. McWilliam Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o97-o99
In 2‐trifluoromethyl‐4‐nitroaniline, C7H5F3N2O2, (I), the molecules lie across a mirror plane in space group Pnma. The molecules are linked by paired N—H?O hydrogen bonds to form a C(8)[R(6)] chain of rings, pairs of which are linked into a molecular ladder by a single C—H?O hydrogen bond. The isomeric 3‐trifluoromethyl‐4‐nitroaniline, (II), has Z′ = 2 in space group P21/c. Each molecule is linked to four others by N—H?O hydrogen bonds to form sheets built from alternating R(12) and R(32) rings. 相似文献
17.
18.
Jacek Zaleski Grzegorz Spaleniak Janusz B. Kyzio 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o627-o629
The geometries of the thiazole ring and the nitramino groups in N‐(3H‐thiazol‐2‐ylidene)nitramine, C3H3N3O2S, (I), and N‐methyl‐N‐(thiazol‐2‐yl)nitramine, C4H5N3O2S, (II), are very similar. The nitramine group in (II) is planar and twisted along the C—N bond with respect to the thiazole ring. In both structures, the asymmetric unit includes two practically equal molecules. In (I), the molecules are arranged in layers connected to each other by N—H⋯N and much weaker C—H⋯O hydrogen bonds. In the crystal structure of (II), the molecules are arranged in layers bound to each other by both weak C—H⋯O hydrogen bonds and S⋯O dipolar interactions. 相似文献
19.
Hiroyuki Hosomi Shigeru Ohba Yoshikatsu Ito 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e149-e150
In the three title crystal structures 4‐(dimethylamino)pyridinium 2,4‐dinitrobenzoate, (I), 4‐(dimethylamino)pyridinium 3,4‐dinitrobenzoate, (II), and 4‐(dimethylamino)pyridinium 3,5‐dinitrobenzoate, (III), all C7H11N2+·C7H3N2O6?, the ions are connected by an N—H?O hydrogen bond. Dihedral angles between the pyridine and phenyl rings are 69.9 (1), 26.7 (1) and 56.2 (1)° in (I), (II) and (III), respectively. Donor–acceptor π–π stacking is observed in (II) and (III), but not in (I). 相似文献
20.
Renata Toplak Nina Lah Julija Volmajer Ivan Leban Alenka Majcen Le Marchal 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(9):o502-o505
The reaction of different substituted α‐cyanooxiranes with thiourea resulted in the formation of the 2‐aminothiazolinone derivative 2‐amino‐5‐(2,5‐dimethoxyphenyl)‐1,3‐thiazol‐4(5H)‐one, C11H12N2O3S, (I), and the 2‐aminothiazole derivative ethyl 2‐amino‐5‐(2,5‐dimethoxyphenyl)‐1,3‐thiazole‐4‐carboxylate, C14H16N2O4S, (II). The geometries of the two crystallographically independent molecules in (II) are nearly identical but mirror related. The crystal structures of both compounds contain two types of intermolecular hydrogen bonds. 相似文献