共查询到20条相似文献,搜索用时 10 毫秒
1.
Stepan Boitsov Jon Songstad Karl W. Trnroos 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o145-o147
The crystal structure of the title compound, C9H6F3N, at 123 K contains molecules linked together via several C—H?F and C—H?N contacts, the strongest of which are 2.58 and 2.65 Å, respectively. Apparently, an F atom in the CF3 group is able to compete with a cyano N atom for aromatic H atoms but is less prone to interact with the more acidic methylene H atoms. The Ph–CH2CN torsion angle is ?6.4 (2)° and the planar phenyl ring exhibits a typical deformation of the endo angles at the ipso‐C atoms, due to the difference in the electron‐withdrawing power of the CF3 and CH2CN substituents. 相似文献
2.
Dianne D. Ellis Anthony L. Spek 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e547-e548
In the title compound, [Ag{P(C6H5)}4][B{P(C6H5)}4]·CH3CN, the Ag ion resides on a crystallographic twofold rotation axis and is tetrahedrally coordinated. There is a disparity between the two independent Ag—P distances. This is due, in part, to the temperature differences (all previous determinations are at room temperature) but also to the packing effects of various anions. 相似文献
3.
Peter C. Junk Brian W. Skelton Allan H. White 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):m289-m290
Anhydrous aluminium(III) tribromide crystallizes from acetonitrile as a disolvate, AlBr3·2MeCN, in the form [AlBr(C2H3N)5][AlBr4]2·C2H3N, which is isomorphous with its orthorhombic chloride counterpart. 相似文献
4.
Hiroyuki Ishida Setsuo Kashino 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):476-479
2,5‐Dichloro‐3,6‐dihydroxy‐1,4‐benzoquinone (chloranilic acid) forms X—H?Y (X, Y = N or O) and C—H?Cl hydrogen bonds with pyrazole and imidazole to afford bis(pyrazolium) dichloroanilate and bis(imidazolium) dichloroanilate, (I) and (II), both 2C3H5N2+·C6Cl2O42?, and imidazolium chloroanilate acetonitrile solvate, C3H5N2+·C6HCl2O4?·C2H3N, (III). Their crystal structures demonstrate three novel supramolecular architectures based on supramolecular synthons to build a ladder, (I), a two‐dimensional network, (II), and a flat ribbon, (III). 相似文献
5.
J. Jeyakanthan S. Shanmuga Sundara Raj D. Velmurugan Hoong‐Kun Fun T. Joseph Rajan V. T. Ramakrishnan 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1109-1112
The title compounds, 10‐benzoylamino‐1,2,3,4,5,6,7,8,9,10‐decahydroacridine‐1,8‐dione monohydrate, C20H20N2O3·H2O, and 10‐p‐toluoylamino‐1,2,3,4,5,6,7,8,9,10‐decahydroacridine‐1,8‐dione monohydrate, C21H22N2O3·H2O, consist of partially hydrogenated acridine moieties with one benzoylamino substituent on the central ring. The acridine moiety suffers considerable deviations from planarity. The central ring in the acridine moiety is a boat, while the outer rings adopt sofa conformations. 相似文献
6.
Michael Bolte Karl Hensen Alexander Faber 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):e524-e525
In the course of an attempt to synthesize tetrakis(3,5‐dimethylpyridine)dihydridosilicon dibromide, crystals of its acetonitrile disolvate, C28H38N4Si2+·2Br?·2C2H3N, (I), and of 3,5‐dimethylpyridinium bromide, C7H10N+·Br?, (II), were obtained in the same reaction flask. They have both been structurally characterized. 相似文献
7.
Two Uranyl Complexes with Pyromellitic Acid. A Heterometallic Complex with U=O–CuII Interaction
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Lingling Liang Yige Cai Xiang Li Ronglan Zhang Jianshe Zhao Chiyang Liu Ng Seik Weng 《无机化学与普通化学杂志》2015,641(10):1744-1748
Two uranyl complexes based on pyromellitic acid were hydrothermally synthesized, and their X‐ray single‐crystal diffraction structures were determined. Complex [UO2(Hbtec)]–(Himd)+ · H2O ( 1 ) (H4btec = pyromellitic acid, imd = imidazole), is an ionic complex, which shows a typical (4, 4) topological structure in the space. A heterometallic complex, UO2Cu(btec)(phen) ( 2 ) (phen = 1,10‐phenanthroline) results from the reaction of uranyl nitrate and copper(II) bromide with pyromellitic acid. The structure of complex 2 revealed that the chains of UO7 and CuO3N2 units were connected to each other through the carboxyl groups and U=O–Cu interactions to create a two‐dimensional framework. 相似文献
8.
Francesco Foti Giovanni Grassi Francesco Risitano Salvatore La Rosa 《Journal of heterocyclic chemistry》2001,38(2):539-540
The synthesis of a series of 3‐Imidazolylazole derivatives using cycloaddition reactions of a useful new nitrile oxide is described. 相似文献
9.
Andrzej Gzella Danuta Brzda ukasz Koroniak Maria D. Rozwadowska 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o503-o506
In the two title optically active tetrahydroisoquinoline derivatives, namely 3‐hydroxymethyl‐4‐phenyl‐1,2,3,4‐tetrahydroisoquinolin‐2‐ium bromide methanol hemisolvate, C16H18NO+·Br?·0.5CH3OH, (IIb), and 2‐formyl‐3‐hydroxymethyl‐4‐phenyl‐1,2,3,4‐tetrahydroisoquinoline, C17H17NO2, (III), the absolute configurations have been confirmed as 3R,4R by structure refinement using Bijvoet‐pair reflections. The hydroxymethyl and phenyl groups in (IIb) are oriented in equatorial and pseudo‐equatorial positions, respectively, whereas in (III), the corresponding groups are in axial and pseudo‐axial positions, respectively; the hydroxymethyl and phenyl groups are trans with respect to one another in both structures. The heterocyclic rings in (IIb) and (III) adopt envelope conformations inverted with respect to each other. In both structures, the molecules are linked through hydrogen bonds. 相似文献
10.
Yanqin Yang Dapeng Zhao Kailong Yuan Guojun Zhou Yu Wang Yanmeng Xiao 《Natural product research》2015,29(10):908-913
The crude methanol extract of roots of Lithospermum erythrorhizon was subjected to successive chromatographic fractionation which afforded two new dimeric naphthoquinone derivatives shikometabolin E (2) and shikometabolin F (3) as well as one known compound shikometabolin A (1). The structures of compounds 1–3 were elucidated by using UV, MS, 1D and 2D NMR spectroscopic analysis. The two new dimeric naphthoquinone derivatives showed significant neuraminidase inhibitory activities. 相似文献
11.
Gerhard Baum Alexander J. Blake Dieter Fenske Peter Hubberstey Carine Julio Matthew A. Withersby 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):m542-m544
Molecules of the title compound, [Cu(C2H3N)(C11H9N5)(C6H6N2O)](BF4)2·2C2H3N, comprise (acetonitrile)[2,6‐bis(pyrazol‐1‐yl)pyridine](isonicotinamide)copper(II) cations, tetrafluoroborate anions and lattice acetonitrile molecules. The cations have distorted square‐pyramidal geometries in which the N3‐donor, viz. 2,6‐bis(pyrazol‐1‐yl)pyridine, and the N‐donor, viz. the isonicotinamide ligand, occupy the four basal positions, with the coordinated acetonitrile N‐donor atom occupying the apical position. Pairs of cations are linked by N—H?F hydrogen bonds through tetrafluoroborate anions, forming centrosymmetric dimers, which are further linked by C—H?O hydrogen bonds into two‐dimensional undulating sheets, three of which interpenetrate to generate a two‐dimensional network. 相似文献
12.
The reaction of nitrile oxides with tropone yields a mixture of at least 8 products, the structures of which are based on spectral and chemical evidence. Both addition of the 1,3-dipole to the carbonyl group and cycloadditions to the CC double bonds system have been observed. Peri-, regio- and stereo-selectivity of the 1,3-dipole cycloaddition are discussed and rationalized on the basis of simple perturbation theory approach. 相似文献
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16.
Max Keller Mohan M. Bhadbhade Roger W. Read 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(6):o240-o246
In two dibenzodiazepinones, viz. the tricyclic core structure, 5H‐dibenzo[b,e]diazepin‐11(10H)‐one, C13H10N2O, and an acylated derivative, 1‐(11‐hydroxy‐5H‐dibenzo[b,e]diazepin‐5‐yl)‐2‐{4‐[3‐(1H‐imidazol‐1‐yl)propyl]piperidin‐1‐yl}ethanone ethanol monosolvate, C26H29N5O2·C2H5OH, dimeric association via hydrogen‐bond bridging between the cyclic amide entities is evident, but there are considerable differences between the parent compound and the amidated derivative. Highly consistent with reported structures of related tricyclic lactams, two molecules of the nonsubstituted compound are bridged through two N—H...O hydrogen bonds across a crystallographic centre of symmetry and the bond lengths of the cyclic amide entity correspond to the amino–oxo (lactam) tautomeric form. In contrast, the structure of the derivative shows two similar, but crystallographically unique, molecules hydrogen bonded into a dimeric unit exhibiting an approximate (noncrystallographic) C2 axis. The bond lengths of the two derivative cyclic amide groups support their potential presence in the hydroxyimine (lactim) tautomeric forms, with the resulting possibility of intermolecular tautomerism. Likely driving forces for the two extreme configurations are discussed. 相似文献
17.
Matthew J. Hallam Colin A. Kilner Malcolm A. Halcrow 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):m445-m446
The title compound, [Cu2(C8H6N3)2(C2H3N)2](ClO4)2, contains a centrosymmetric dinuclear dication, with square‐pyramidal CuII centres linked by two 1,2‐pyrazolide bridging groups. There is a weak apical interaction between each Cu ion and a perchlorate O atom. 相似文献
18.
[reaction: see text] Intramolecular nitrile oxide-alkene cycloaddition (INOC) of sugar derivatives with one to four free hydroxyl group(s) is reported. The INOC reaction, using chloramine-T, in the presence of silica gel, to generate nitrile oxides from oximes, proceeded smoothly to afford five- or six-membered carbocycles in good to excellent yields. This new methodology alleviates protection/deprotection steps and makes the synthetic route shorter and more efficient. 相似文献
19.
Xi‐Rui Zeng Xiao‐Niu Fang Shie‐Ming Peng Hsiu‐Mei Lin 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):m497-m498
The crystal structure of the title compound, [Cu2(C2F3O2)2(C10H8N3O)2]·2CH3CN, contains discrete [Cu2(CF3COO)2(O‐dpa)2] molecules (O‐dpaH is di‐2‐pyridylamine 1‐oxide) which have imposed crystallographic twofold symmetry and an acetonitrile molecule of solvation. The O‐dpa− ligand is both bidentate and bridging, linking two Cu atoms with a separation of 3.4270 (11) Å. Each Cu atom is surrounded by four coordinated atoms that are almost coplanar, with dimensions Cu—N = 1.940 (2) and 1.984 (3) Å, and Cu—O = 1.912 (2) and 1.945 (2) Å. 相似文献
20.
Anthony Linden Cihat afak Rahime imek Miyase G. Gündüz 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(2):o80-o84
The title compounds, benzyl 4‐(3‐chloro‐2‐fluorophenyl)‐2‐methyl‐5‐oxo‐4,5,6,7‐tetrahydro‐1H‐cyclopenta[b]pyridine‐3‐carboxylate, C23H19ClFNO3, (I), and 3‐pyridylmethyl 4‐[2‐fluoro‐3‐(trifluoromethyl)phenyl]‐2,6,6‐trimethyl‐5‐oxo‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxylate, C26H24F4N2O3, (II), belong to a class of 1,4‐dihydropyridines whose members sometimes display calcium modulatory properties. The 1,4‐dihydropyridine ring in each structure has a shallower than usual shallow‐boat conformation and is nearly planar in (I). In each structure, the halogen‐substituted benzene ring is oriented such that the halogen substituents are in a synperiplanar orientation with respect to the 1,4‐dihydropyridine ring plane. The oxocyclopentene ring in (I) is planar, while the oxocyclohexene ring in (II) has a half‐chair conformation, which is less commonly observed than the envelope conformation usually found in related compounds. In (I), the frequently observed intermolecular N—H...O hydrogen bond between the amine group and the carbonyl O atom of the oxocyclopentene ring of a neighbouring molecule links the molecules into extended chains; there are no other significant intermolecular interactions. By contrast, the amine group in (II) forms an N—H...N hydrogen bond with the pyridine ring N atom of a neighbouring molecule. Additional C—H...O interactions complete a two‐dimensional hydrogen‐bonded network. The halogen‐substituted benzene ring has a weak intramolecular π–π interaction with the pyridine ring. A stronger π–π interaction occurs between the 1,4‐dihydropyridine rings of centrosymmetrically related molecules. 相似文献