共查询到20条相似文献,搜索用时 15 毫秒
1.
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
2.
Orhan Büyükgüngr Mustafa Odabaolu idem Albayrak Peter Lnnecke 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o470-o472
The title complex, 2C5H7N2+·C4H2O42−·C4H4O4, contains cyclic eight‐membered hydrogen‐bonded rings involving 2‐aminopyridinium and fumarate ions. The fumaric acid molecules and fumarate ions lie on inversion centers and are linked into zigzag chains by O—H⋯O hydrogen bonds. The dihedral angle between the pyridinium ring and the hydrogen‐bonded fumarate ion is 7.60 (4)°. The fumarate anion is linked to the pyridinium cations by intermolecular N—H⋯O hydrogen bonds. The heterocycle is fully protonated, thus enabling amine–imine tautomerization. 相似文献
3.
Hiroyuki Ishida Bilkish Rahman Setsuo Kashino 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):876-879
2‐Chloro‐4‐nitrobenzoic acid and 2‐chloro‐5‐nitrobenzoic acid form O—H?N hydrogen bonds with pyrazine to afford 2:1 complexes of 2C7H4ClNO4·C4H4N2, (I) and (II), respectively, that are located on inversion centers. The 2C7H4ClNO4·C4H4N2 units in both complexes are connected by weak C—H?O hydrogen bonds; the units build a three‐dimensional hydrogen‐bond network in (I) and a ribbon structure in (II). 相似文献
4.
Daniel E. Lynch Ian McClenaghan 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):830-832
The structure of the title compound, C9H8N4, comprises non‐planar molecules that associate via pyrimidine N—H?N dimer R(8) hydrogen‐bonding associations [N?N 3.1870 (17) Å] and form linear hydrogen‐bonded chains via a pyrimidine N—H?N(pyridyl) interaction [N?N 3.0295 (19) Å]. The dihedral angle between the two rings is 24.57 (5)°. The structure of the 1:1 adduct with 4‐aminobenzoic acid, C9H8N4·C7H7NO2, exhibits a hydrogen‐bonding network involving COOH?N(pyridyl) [O?N 2.6406 (17) Å], pyrimidine N—H?N [N?N 3.0737 (19) and 3.1755 (18) Å] and acid N—H?O interactions [N?O 3.0609 (17) and 2.981 (2) Å]. The dihedral angle between the two linked rings of the base is 38.49 (6)° and the carboxylic acid group binds to the stronger base group in contrast to the (less basic) complementary hydrogen‐bonding site. 相似文献
5.
Suchada Chantrapromma Hoong‐Kun Fun Ibrahim Abdul Razak Nisakorn Saewon Chatchanok Karalai Kan Chantrapromma 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e598-e599
In the title compound, C19H20O8, the benzene rings are nearly perpendicular to each other [dihedral angle 80.2 (2)°]. The carboxy group is twisted out while both the methoxy and acetyl groups are almost coplanar with their attached benzene rings. The hydroxy group is involved in an intramolecular O—H?O hydrogen bond with the acetyl O atom and the compound is connected through an intermolecular O—H?O contact to form a dimer. The crystal structure is stabilized by intermolecular O—H?O hydrogen bonds. 相似文献
6.
Rodolfo Moreno‐Fuquen Eustaquio Vinicius Ribeiro de Castro Margarita Moreno Regina Helena De Almeida Santos Angela Marcela Montao 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):206-207
In the title co‐crystal, C7H5NO4·C5H4N2O3, the two components are linked by an intermolecular hydrogen bond between the O—H and N—O groups [O?O 2.577 (3) Å]. The interplanar angle between the planes of the rings of the molecules is 5.3 (2)°. The rings are stacked in the crystal with a mean interplanar distance of 3.279 (3) Å. 相似文献
7.
Xiao‐Ming Ren Hai‐Fang Li Pei‐Heng Wu Qing‐Jin Meng 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1022-1024
In the title complex, 2‐methyl‐1‐(4‐nitrobenzyl)pyridinium bis(1,2‐dicyanoethene‐1,2‐dithiolato)nickelate(III), (C13H13N2O2)[Ni(C4N2S2)2], the most prominent general structural feature of the complex is the completely segregated columnar stacks of anions and cations. Within the cation column, there may be stacking interactions between adjacent nitro groups and benzene rings. 相似文献
8.
Brian T. Holmes Clifford W. Padgett William T. Pennington 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):o114-o116
The title compound, C34H26N4·2CH2Cl2, lies about an inversion center. The solvent molecules interact with the benzene molecule both through C—H⃛N hydrogen bonding to span pyridine N atoms of adjacent vinyl groups, possibly stabilizing the rotational conformation observed, and through a π interaction between a dichloromethane Cl atom and a pyridyl ring C—C bond of a c‐glide‐related molecule. The benzene molecules form stacks along the a axis such that two of the four olefin groups are properly oriented for photoreactivity (2+2 cyclodimerization). 相似文献
9.
10.
Prabodhika Mallikaratchy Richard E. Norman Frank R. Fronczek Thomas Junk 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o571-o574
All three title compounds, prepared from bis(3,5‐dimethyl‐2‐nitrophenyl)ditellurium, exhibit high degrees of intramolecular Te—O coordination. Their Te—O distances increase in the order C8H8BrNOTe < C8H8BrNO2Te < C8H8Br3NO2Te, with distances of 2.165 (3), 2.306 (1) and 2.423 (6) Å, respectively, indicating that C8H8BrNOTe may be more aptly described as 1‐bromo‐4,6‐dimethyl‐2,1,3‐benzoxatellurazole. 相似文献
11.
Robert W. Janes 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):362-364
The title compound, C9H8FN5·C3H7NO, contains two independent complexes in the asymmetric unit, each consisting of one 3,5‐diamino‐6‐(2‐fluorophenyl)‐1,2,4‐triazine molecule and one dimethylformamide solvent molecule. One triazine molecule is disordered over two conformations within the crystal, the occupancies being 62 (1) and 38 (1)%. The phenyl ring of this molecule resolves into two conformations rotated by almost 180° about the bridging bond between the two rings, while the triazine rings approximately superimpose on each other. The triazine molecules of the asymmetric unit differ in the dihedral angles between their respective phenyl and triazine ring planes, these being 57.6 (2)° for the fully occupied, and 76.9 (6) and 106.8 (8)° for the partially occupied molecules. An extensive network of hydrogen bonds maintains the crystal structure. 相似文献
12.
Ming‐Lin Guo 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o690-o692
The title adduct, C5H14N22+·C8H3NO62−·C8H5NO6·H2O, crystallizes in the monoclinic space group P21. All O atoms of the 4‐nitrophthalate anions and neutral 4‐nitrophthalic acid molecules are involved in hydrogen bonding with the piperazine dication and the water molecule of crystallization. 相似文献
13.
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
14.
Manfredo Hrner Almir Luis Brancher Angela Silva Jairo Bordinhao Ccilia M. Mssmer 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):o303-o304
The crystal structure of the title compound, C14H12N4O3, shows that the stereochemistry about the N=N double bond of the N=N—N(H) moiety is trans. The whole molecule is almost planar (r.m.s. deviation = 0.0654 Å), the interplanar angle between the phenyl rings being 0.7 (1)° and the largest interplanar angle being that between the phenyl ring and the nitro group of the 4‐nitrophenyl substituent [11.5 (2)°]. Intermolecular N—H⋯O interactions between molecules related by translation give rise to chains along the [110] and [10] directions, and these chains are held together by N⋯O π–π interactions. An unequal distribution of the double‐bond character among the N atoms suggests a delocalization of π electrons over the diazoamine group and the adjacent aryl substituents. 相似文献
15.
Abdul Hamid Othman Yang‐Yi Yang Xiao‐Ming Chen Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):e318-e319
The three‐coordinate Ag atom in the title compound, [Ag(C7H3N2O6)(C18H15P)2], shows trigonal–planar coordination [P—Ag—P = 147.1 (1)° and ΣAg = 359.0 (3)°]. Adjacent molecules are linked through the O atoms of adjacent nitro groups [Ag?O = 3.205 (3) and 3.302 (4) Å] into a zigzag chain running parallel to the c axis. 相似文献
16.
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
17.
Kouzou Matsumoto Dr. Takuya Inagaki Tatsuo Nehira Dr. Masaki Kannami Dr. Daisuke Inokuchi Hiroyuki Kurata Dr. Takeshi Kawase Dr. Gennaro Pescitelli Dr. Masaji Oda Prof. Dr. 《化学:亚洲杂志》2007,2(8):1031-1036
The title compound, a prototypical chiral molecule based on a tetraarylmethane framework, has been synthesized in five steps from (2‐pyridyl)‐(3‐pyridyl)ketone. X‐ray crystallographic analysis revealed the tetraarylmethane framework of the molecule but did not determine the positions of the nitrogen atoms because the crystal is a racemic compound and the aryl groups are disordered in the crystal. The optical resolution of the title compound was achieved by chiral HPLC with a Chiralcel OD column. The CD spectra of the two fractions in acetonitrile exhibited opposite signs as expected for a pair of enantiomers. Their CD spectra are changed in 2 M HCl due to protonation. The calculated CD curve for the target molecule based on time‐dependent density functional theory (TDDFT) reproduces the experimental result very well, thus suggesting that the first eluted fraction is the R isomer in terms of absolute configuration. 相似文献
18.
Andrei S. Batsanov Judith A. K. Howard 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e467-e468
The title compound, C17H19FN+·Cl?, has an ionic structure, and cations and anions are linked into infinite chains by Cl?H—N—H?Cl hydrogen bonds. The absolute configuration (S) was confirmed. 相似文献
19.
Bi‐Qin Wang Hai‐Biao Yan Zheng‐Qing Huang Yun‐Hua Zhang Jing Sun 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(4):247-251
The title salt, C6H6NO2+·ClO4−·C6H5NO2, was crystallized from an aqueous solution of equimolar quantities of perchloric acid and pyridine‐2‐carboxylic acid. Differential scanning calorimetry (DSC) measurements show that the compound undergoes a reversible phase transition at about 261.7 K, with a wide heat hysteresis of 21.9 K. The lower‐temperature polymorph (denoted LT; T = 223 K) crystallizes in the space group C2/c, while the higher‐temperature polymorph (denoted RT; T = 296 K) crystallizes in the space group P2/c. The relationship between these two phases can be described as: 2aRT = aLT; 2bRT = bLT; cRT = cLT. The crystal structure contains an infinite zigzag hydrogen‐bonded chain network of 2‐carboxypyridinium cations. The most distinct difference between the higher (RT) and lower (LT) temperature phases is the change in dihedral angle between the planes of the carboxylic acid group and the pyridinium ring, which leads to the formation of different ten‐membered hydrogen‐bonded rings. In the RT phase, both the perchlorate anions and the hydrogen‐bonded H atom within the carboxylic acid group are disordered. The disordered H atom is located on a twofold rotation axis. In the LT phase, the asymmetric unit is composed of two 2‐carboxypyridinium cations, half an ordered perchlorate anion with ideal tetrahedral geometry and a disordered perchlorate anion. The phase transition is attributable to the order–disorder transition of half of the perchlorate anions. 相似文献
20.
V. H. Rodrigues M. M. R. R. Costa E. de Matos Gomes E. Nogueira M. S. Belslsey 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):o699-o701
In the 1:1 adduct formed between l ‐phenylalanine and 4‐nitrophenol [alternative IUPAC name: (2S)‐2‐ammonio‐3‐phenylpropanoate–4‐nitrophenol (1/1)], C9H11NO2·C6H5NO3, the l ‐phenylalanine molecule is in the zwitterionic state. The overall structure is stabilized via strong hydrogen bonding between polar zones and van der Waals interactions between non‐polar zones, which alternate with the polar zones. 相似文献