共查询到20条相似文献,搜索用时 24 毫秒
1.
Shang Shan Duan‐Jun Xu Chen‐Hsiung Hung Jing‐Yun Wu Michael Y. Chiang 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):o135-o136
Crystals of the title compound, C13H10N4O4, were obtained from a condensation reaction of benzaldehyde and 2,4‐dinitrophenylhydrazine. The molecule assumes an approximately planar E configuration. Within the dinitrophenyl moiety, the average distance for the aromatic C—C bonds close to the imino group [1.417 (3) Å] is appreciably longer than the average distance for the other aromatic C—C bonds in the same phenyl ring [1.373 (3) Å]. This increased distance may be a result of the overlap of the non‐bonding orbital of the imino N atom with the π orbitals of the arene. It is likely that π–π stacking exists in the crystal structure. 相似文献
2.
A. Matos Beja J. A. Paixo M. Ramos Silva L. Alte da Veiga A. M. d'A. Rocha Gonsalves A. C. Serra 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):354-355
The molecules of the title compound, C7H5BrO2, form zigzag chains running along the b axis and are stacked in layers perpendicular to the a axis. Intermolecular bonding occurs through hydrogen bonds linking the hydroxyl and carbonyl groups, with an O?O distance of 2.804 (4) Å. The Br atom deviates significantly from the plane of the ring and the aldehyde group is twisted by 7.1 (5)° around the Csp2—Caryl bond. The geometry of the molecule in the crystal is compared to that given by ab initio quantum mechanical calculations for the isolated molecule, using a molecular orbital Hartree–Fock method and density functional theory. 相似文献
3.
Berislav Peri Biserka Koji‐Prodi 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):211-212
The structure of 4,4′‐dibromobenzophenone, C13H8Br2O, was determined at two different temperatures (293 and 103 K). A phase transition was not detected in this temperature range. Its crystal structure was found to be isostructural with that of the diiodo analogue, but not with the structure of the dichloro derivative. 相似文献
4.
Paul E. Kruger Philip R. Mackie Mark Nieuwenhuyzen 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):e532-e532
The title compound, C6HCl3N2O4, is an intermediate in the synthesis of 1,3,5‐trichloro‐2,4,6‐trinitrobenzene. The crystal structure at 153 K shows no major deviations from the previously reported structure at 295 K other than the expected contraction of the a and c axes and, correspondingly, the β angle. 相似文献
5.
F. Betül Kaynak Süheyla
zbey Turan
ztürk Erdal Erta 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):926-928
In the title compound, C17H10S5, the dithiine ring adopts a boat conformation while the dithiole ring has an envelope conformation. The phenyl groups are planar and make dihedral angles of 40.7 (2) and 59.8 (2)° with the best plane of the thiine ring. The shortest intermolecular S?S contact is 3.305 (2) Å. 相似文献
6.
Andrei S. Batsanov 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):e269-e270
The molecule of 3,5‐difluoro‐4‐nitropyridine N‐oxide, C5H2F2N2O3, is twisted around the C—NO2 bond by 38.5 (1)°, while the 3,5‐diamino analogue, 3,5‐diamino‐4‐nitropyridine N‐oxide monohydrate, C5H6N4O3·H2O, adopts a planar conformation stabilized by intramolecular hydrogen bonds, with a significant redistribution of π electrons. 相似文献
7.
Dewey H. Barich Mark T. Zell Douglas R. Powell Eric J. Munson 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(4):o261-o262
The title compounds (both C9H10O4) have nearly planar structures, and the methyl and/or carboxylic acid groups lie out of the molecular plane, as dictated by steric interactions. 2,5‐Dimethoxybenzoic acid (2,5‐DMBA) forms an unusual intramolecular hydrogen bond between the carboxylic acid group and the O atom of the methoxy group in the 2‐position [O⋯O = 2.547 (2) Å and O—H⋯O = 154 (3)°]. 2,4‐DMBA forms a typical hydrogen‐bond dimer with a neighboring molecule. 相似文献
8.
Judge Brown Diwakar M. Pawar Frank R. Fronczek Eric A. Noe 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):o628-o630
Cyclodecyl 4‐nitrophenylacetate, C18H25NO4, has its ten‐membered ring in the expected diamond‐lattice boat–chair–boat [2323] conformation, with the substituent 4‐nitrophenylacetoxy group in the BCB IIIe position. The ester unit has the expected Z conformation, with an O=C—O—C torsion angle of −0.3 (3)°, and the connection to the benzene ring is nearly perpendicular to the ester, with an O=C—C—C torsion angle of 85.5 (2)°. An intermolecular contact exists between the ester C atom and a nitro O atom, having a C⋯O distance of 2.909 (2) Å. 相似文献
9.
J. A. Paixo A. Matos Beja M. Ramos Silva L. Alte da Veiga A. C. Serra 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1348-1350
The title compound, C7H6O2, forms infinite chains where the molecules are hydrogen bonded via the hydroxyl and aldehyde groups, with an O?O distance of 2.719 (3) Å. Interchain interactions are weak. The geometry of the ring differs from the ideal form due to the effect of the substituents. Abinitio (Hartree–Fock self‐consistent field–molecular orbital and density functional theory) calculations for the free molecule reproduce well the observed small distortions of the ring. In the crystal, the geometry deviates from the ideal Cs symmetry of the free molecule, as given by the ab initio calculations. The aldehyde and hydroxyl groups are twisted around the single bonds which join them to the ring as a result of the intermolecular hydrogen‐bond interactions. These are also responsible for an elongation of the hydroxy C—OH bond compared with that calculated for the free molecule. 相似文献
10.
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
11.
9,10‐Diphenyl‐9,10‐epidioxyanthracene and 9,10‐dihydro‐10,10‐dimethoxy‐9‐phenylanthracen‐9‐ol
Anwar Usman Hoong‐Kun Fun Yun Li Jian‐Hua Xu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o308-o310
9,10‐Diphenyl‐9,10‐epidioxyanthracene, C26H18O2, (I), was accidentally used in a photooxygenation reaction that produced 9,10‐dihydro‐10,10‐dimethoxy‐9‐phenylanthracen‐9‐ol, C22H20O3, (II). In both compounds, the phenyl rings are approximately orthogonal to the anthracene moiety. The conformation of the anthracene moiety differs as a result of substitution. Intramolecular C—H⃛O interactions in (I) form two approximately planar S(5) rings in each of the two crystallographically independent molecules. The packing of (I) and (II) consists of molecular dimers stabilized by C—H⃛O interactions and of molecular chains stabilized by O—H⃛O interactions, respectively. 相似文献
12.
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
13.
Leroy Cronin Dave A. Adams David J. Nightingale James H. Clark 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):244-245
The structure of the title compound, C14H7ClN4O5, comprises two nearly coplanar phenyl rings connected via an amido moiety. 相似文献
14.
R. Hema V. Parthasarathi K. Sarkunam M. Nallu Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o703-o705
In both of the title compounds, C23H19ClN2O, (I), and C23H18Cl2N2O, (II), the molecular packing is influenced by weak intermolecular C—H⋯O and C—H⋯π interactions, but despite the chemical similarity of the compounds, the packing in (II) is entirely different from that observed in (I). 相似文献
15.
Ronald D. Clark Angela Romero Oleg Ya. Borbulevych Mikhail Yu. Antipin Vladimir N. Nesterov Tatiana V. Timofeeva 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):336-338
The structures of the potential non‐linear optical (NLO) materials N‐[2‐(isopropylamino)‐5‐nitrophenyl]acetamide, (I) C11H15N3O3, and N‐[2‐(butylamino)‐5‐nitrophenyl]acetamide, (II) C12H17N3O3, have been investigated by X‐ray analysis. To compare them with the structure of N‐[2‐(dimethylamino)‐5‐nitrophenyl]acetamide, (III) C10H13N3O3, a known NLO compound, we had to redetermine the structure of (III), since it was described only briefly in the literature. There are two molecules in the asymmetric unit of compound (I), which have different orientations of the substituents with respect to the benzene ring. The packing of molecules in (II) and (III) contains stacks but both (I) and (II) crystallize in a centrosymmetric space group, which renders them inappropriate for NLO applications. 相似文献
16.
Guo‐Wu Rao Wei‐Xiao Hu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o281-o282
The title compound, C22H24N4O4, was prepared from propyl chloroformate and 3,6‐diphenyl‐1,2‐dihydro‐s‐tetrazine. This reaction yields the title compound rather than dipropyl 3,6‐diphenyl‐1,4‐dihydro‐s‐tetrazine‐1,4‐dicarboxylate. The 2,3‐diazabutadiene group in the central six‐membered ring is not planar; the C=N double‐bond length is 1.285 (2) Å, and the average N—N single‐bond length is 1.401 (3) Å, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie 0.3268 (17) Å from the plane of the ring. The molecule has twofold crystallographic symmetry. 相似文献
17.
Alessandra Crispini Francesco Neve 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o34-o35
The distinctive feature of the crystal structure of 2,6‐diphenylpyridine‐4‐carboxylic acid, C18H13NO2, is the formation of intermolecular O—H?O hydrogen bonds that lead to the formation of centrosymmetric cyclic dimers with R(8) topology. Molecules related by translation along the b axis exhibit strong π–π stacking of aromatic rings, with an average interplanar distance of 3.3 Å. 相似文献
18.
S. Shanmuga Sundara Raj Hoong‐Kun Fun Zhong‐Lin Lu Wen Xiao Xiao‐Yang Gong Chang‐Ming Gen 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):1015-1016
The whole molecule of the title compound, C19H14N4O2, is essentially planar, with a highly conjugated π system. In the crystal, the molecules are packed as chains along the [011] direction connected by O—H?N intermolecular hydrogen bonds. 相似文献
19.
Viktor Kettmann Jan Lokaj Jozef Koíek Josef Pikryl Vladimír Mach
ek 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o143-o145
The molecule of the title compound, C17H17N5O2S, consists of three π systems, viz. two aromatic rings and the triazene moiety, which are mutually deconjugated although coplanar. The n‐butyl chain is roughly perpendicular to the molecular plane, with the terminal methylene and methyl groups disordered between two equally populated positions. The molecules in the crystal associate in an antiparallel fashion, forming dimers across the centre of symmetry, the principal intradimer interaction being stacking of the π‐electron portions of the molecules. 相似文献
20.
Jos S. Casas Emilia García‐Martínez María Soledad García‐Tasende Agustín Snchez Jos Sordo Ezequiel M. Vzquez‐Lpez María Jos Vidarte 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):932-933
The title compound, [SnCl2(CH3)(C6H5)(C5H8N2)2], was obtained by reaction of dichloromethylphenyltin(IV) and 3,5‐dimethylpyrazole (dmpz) in chloroform, and was recrystallized from acetone. The structure consists of octahedral all‐trans [SnMePhCl2(dmpz)2] molecules, with the Sn atom coordinated to two C [Sn—C 2.127 (5) and 2.135 (4) Å], two Cl [Sn—Cl 2.5753 (8) Å] and two N atoms [Sn—N 2.357 (3) Å]. The dmpz ligands, bound to the metal through their unprotonated N atoms, form weak intra‐ and intermolecular hydrogen bonds with the Cl ligands via their NH groups, giving rise to a polymeric chain along the c axis. 相似文献