共查询到20条相似文献,搜索用时 31 毫秒
1.
G. Chevrier J. M. Kiat J. Guida A. Navaza 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):i59-i62
Crystals of barium pentacyanonitrosylferrate trihydrate (barium nitroprusside trihydrate), Ba[Fe(CN)5(NO)]·3H2O, have been studied by neutron diffraction in order to examine the structural behaviour of the compound in the 20–120 K temperature range and to determine the structure at 105 K. The results show the existence of a new crystal phase of the compound at 80 K (with a duplicated a parameter), which still exists at 20 K. The crystal structure at 105 K shows a rearrangement of the water molecules, which results in an ordered structure with P1 symmetry. Two of the four independent nitroprusside cations are rotated by 4.5° around the [100] direction. 相似文献
2.
Anwar Usman Suchada Chantrapromma Hoong-Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(12):1443-1446
The title compound, 3,5,7-triaza-1-azoniatricyclo[3.3.1.13,7]decane 2,4-dinitrophenolate monohydrate, C6H13N4+·C6H3N2O5−·H2O, the 1:1 hydrate adduct of hexamethylenetetramine (HMT) and 2,4-dinitrophenol, undergoes a temperature phase transition. In the room-temperature phase, the adduct crystallizes in the monoclinic P21/m space group, whereas in the low-temperature phase, the adduct crystallizes in the triclinic P space group. This phase transition is reversible, with the transition temperature at 273 K, and the phase transition is governed by hydrogen bonds and weak interactions. In both these temperature-dependent polymorphs, the crystal structure is alternately layered with sheets of hexamethylenetetramine and sheets of dinitrophenol stacked along the c axis. The hexamethylenetetramine and dinitrophenol moieties are linked by intermolecular hydrogen bonds. The water molecule in the adduct plays an important role, forming O—H⋯O hydrogen bonds which, together with C—H⋯O hydrogen bonds, bridge the adducts into molecular ribbons. Extra hydrogen bonds and weak interactions exist for the low-temperature polymorph and these interconnect the molecular ribbons into a three-dimensional packing structure. Also in these two temperature-dependent polymorphs, dinitrophenol acts as a hydrogen-bond acceptor and HMT acts as a hydrogen-bond donor. 相似文献
3.
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
4.
Anwar Usman Suchada Chantrapromma Hoong‐Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):m45-m47
The title compound, bis(2,4‐dinitrophenolato‐κ2O,O′)(1,4,7,10,13,16‐hexaoxadecane‐κ6O)barium(II), [Ba(C6H3N2O5)2(C12H24O6)], is a 1:1 complex of barium(II)–2,4‐dinitrophenolate and 1,4,7,10,13,16‐hexaoxacyclooctadecane (18‐crown‐6). Its structure is located on a crystallographic inversion centre. The temperature dependence of the crystal structure has been studied. The monoclinic β angle of the P21/n space group increases with increasing temperature. The packing structure of the complex is stabilized by intermolecular C—H?O interactions. 相似文献
5.
L. Vijayalakshmi V. Parthasarathi P. Manishanker 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):e403-e404
The crystal structure of the title compound, C13H10ClNO, confirms that it exists as a nitrone. The geometry about C=N is Z. The relevant torsion angles indicate trans and cis conformations around the nitrone bond. 相似文献
6.
Bartosz Zarychta Zdzisaw Daszkiewicz Janusz B. Kyzio Jacek Zaleski 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(10):o564-o566
Two isomeric products (C8H10N2O4S) of the rearrangement of 3‐methanesulfonyl‐N‐methyl‐N‐nitroaniline have been investigated, viz. 3‐methanesulfonyl‐N‐methyl‐2‐nitroaniline, which was the main product of the rearrangement, and 5‐methanesulfonyl‐N‐methyl‐2‐nitroaniline. In both molecules, the aromatic rings are appreciably deformed towards ortho‐quinonoidal geometry by electronic and steric interactions. The crystal structure is stabilized, in both cases, by weak C—H⋯O hydrogen bonds. 相似文献
7.
Arthur J. Schultz Brian N. Figgis Alexandre N. Sobolev 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):1289-1291
The crystal structure of Na2Fe(CN)5(NO)·2D2O, disodium pentacyanonitrosylferrate(III) bis(dideuterium oxide), has been determined by X‐ray diffraction at 11 and 293 K, and by neutron diffraction at 15 K. The accurate and extensive data sets lead to more precise determinations than are available from earlier work. The agreement in atomic positional and displacement parameters between the determinations at low temperature is very good. 相似文献
8.
Yoriko Sonoda Seiji Tsuzuki Nobuyuki Tamaoki Midori Goto 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):o196-o200
The crystal structures of the four E,Z,E isomers of 1‐(4‐alkoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, namely (E,Z,E)‐1‐(4‐methoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, C19H17NO3, (E,Z,E)‐1‐(4‐ethoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, C20H19NO3, (E,Z,E)‐1‐(4‐nitrophenyl)‐6‐(4‐n‐propoxyphenyl)hexa‐1,3,5‐triene, C21H21NO3, and (E,Z,E)‐1‐(4‐n‐butoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, C22H23NO3, have been determined. Intermolecular N⋯O dipole interactions between the nitro groups are observed for the methoxy derivative, while for the ethoxy derivative, two adjacent molecules are linked at both ends through N⋯O dipole–dipole interactions between the N atom of the nitro group and the O atom of the ethoxy group to form a supramolecular ring‐like structure. In the crystal structures of the n‐propoxy and n‐butoxy derivatives, the shortest intermolecular distances are those between the two O atoms of the alkoxy groups. Thus, the nearest two molecules form an S‐shaped supramolecular dimer in these crystal structures. 相似文献
9.
Laura Andrau Jonathan White 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(2):o60-o61
The crystal structure of N‐methyl‐4‐piperidyl 2,4‐dinitrobenzoate, C13H15N3O6, (I), at 130 (2) K reveals that, in the solid state, the molecule exists in the equatorial conformation, (Ieq). Thus, the through‐bond interaction present in the axial conformation, (Iax), is not strong enough to overcome the syn–diaxial interactions between the axial methyl substituent and the axial H atoms on the two piperidyl ring C atoms either side of the ester‐linked ring C atom. The carboxylate group in (I) is orthogonal to the aromatic ring, in contrast with other 2,4‐dinitrobenzoates, which are coplanar. The piperidyl–ester C—O bond distance is 1.467 (3) Å, which is actually shorter than other equatorial cyclohexyl–ester C—O distances. This shorter piperidyl–ester C—O bond distance is due to the reduced electron demand of the orthogonal ester group. 相似文献
10.
Jin Yang Jian‐Fang Ma Ying‐Chun Liu Guo‐Li Zheng Li Li Jing‐Fu Liu Ning‐Hai Hu Heng‐Qing Jia 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):m613-m614
In the crystal structure of the title compound, (NH4)[AsO2(OH)(C6H4NO2)], the 4‐nitrophenylarsonate anions and ammonium cations are linked through hydrogen bonds to form infinite chains along the b axis. The hydroxyl O atom of the 4‐nitrophenylarsonate anion acts as both an acceptor and a donor of hydrogen bonds. All atoms are located in general positions. 相似文献
11.
David Drouard Sandrine Py Marie‐Thrse Averbuch Christian Philouze Yannick Valle 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1079-1080
The preparation and crystal structure of the title compound, C20H25NO2, are described. The N atom substituent of the nitrone function adopts a conformation which minimizes the 1,3‐allylic strain. 相似文献
12.
Michael Becker Martin Jansen 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):347-348
Single crystals of the title compound have been grown by annealing microcrystalline zinc cyanamide at 843 K in silver crucibles. Zn(CN2) crystallizes as colourless prisms. The crystal structure is composed of corner‐linked ZnN4/2 tetrahedra. Carbon and nitrogen form (CN2)2? dumb‐bells with the C atom on a twofold axis. Nitrogen is approximately trigonally planar, coordinated by two Zn atoms and one C atom. 相似文献
13.
Alexander D. Vasiliev Alexander M. Astachov Oksana A. Golubtsova Konstantin V. Pekhotin Mark V. Rogozin Ludmila A. Kruglyakova Rudolf S. Stepanov 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1101-1102
The molecule of the title compound, C2H2N6O4, consists of three planar fragments, namely a tetrazole ring, a nitromethyl group and a nitro group. The nitro group and the tetrazole cycle are arranged in the same plane, but the planar nitromethyl group is located nearly orthogonal to this plane. The molecules are packed in the crystal via van der Waals interactions. 相似文献
14.
Vladimir V. Chernyshev Victor A. Tafeenko Svetlana Yu. Ryabova Eduard J. Sonneveld Hendrik Schenk 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):982-984
The evidence for thermal isomerization of the title compound, C24H15N5O2, into 2‐[(4‐nitrophenyl)phenylamino]‐5H‐pyrido[3,2‐b]indole‐3‐carbonitrile has been obtained as a consequence of crystal structure determinations from laboratory powder data. 相似文献
15.
Vladimir N. Nesterov Tatiana V. Timofeeva Oleg Ya. Borbulevych Mikhail Yu. Antipin Ronald D. Clark 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):971-975
A combinatorial chemistry approach has been used to synthesize an array of Schiff bases, five of which, namely N‐[(E,2E)‐3‐(4‐methoxyphenyl)‐2‐propenylidene]‐3‐nitroaniline, C16H14N2O3, (1a), N‐[(E,2E)‐3‐(4‐methoxyphenyl)‐2‐propenylidene]‐4‐nitroaniline, C16H14N2O3, (2a), N‐{(E,2E)‐3‐[4‐(dimethylamino)phenyl]‐2‐propenylidene}‐3‐nitroaniline, C17H17N3O2, (1b), N‐{(E,2E)‐3‐[4‐(dimethylamino)phenyl]‐2‐propenylidene}‐4‐nitroaniline, C17H17N3O2, (2b), and N‐{(E,2E)‐3‐[4‐(dimethylamino)phenyl]‐2‐propenylidene}‐2‐methyl‐4‐nitroaniline, C18H19N3O2, (3b), have been structurally characterized. A stack structure is observed for (1a) and (1b) in the crystal phase. Experimental and calculated molecular structures are discussed for these compounds which belong to a chemical class having potential applications as non‐linear optical materials. 相似文献
16.
Sergei D. Kirik Alexander I. Blokhin Ruslan F. Mulagaleev 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(10):m445-m447
The water‐insoluble title compound, octakis(μ‐acetato‐κ2O:O)octakis(μ‐nitroso‐κ2N:O)octapalladium(II), [Pd8(CH3COO)8(NO)8], was precipitated as a yellow powder from a solution of palladium nitrate in nitric acid by adding acetic acid. Ab initio crystal structure determination was carried out using X‐ray powder diffraction techniques. Patterson and Fourier syntheses were used for atom locations, and the Rietveld technique was used for the final structure refinement. The crystal structure is of a molecular type. The skeleton of the [Pd8(CH3COO)8(NO)8] molecule is constructed as a tetragonal prism with Pd atoms at the vertices. The eight NO− groups are in bridging positions along the horizontal edges of the prism. The N and O atoms of each nitroso group coordinate two different Pd atoms. The vertical edges present Pd⋯Pd contacts with a short distance of 2.865 (1) Å. These Pd atoms are bridged by a pair of acetate groups in a cis orientation with respect to each other. The complex has crystallographically imposed 4/m symmetry; all C atoms of the acetate groups are on mirror planes. The unique Pd atom lies in a general position and has square‐planar coordination, consisting of three O and one N atom. 相似文献
17.
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
18.
Marco Crisma Claudio Toniolo 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):o215-o217
The preparation, characterization, and molecular and crystal structures of the title compound [IUPAC name: 2‐nitrophenyl 2‐methyl‐2‐(para‐toluenesulfonylamino)propanoate], C17H18N2O6S, are reported. The phenyl group is almost perpendicular to the plane of the adjacent ester moiety. One O atom of the nitro group is wedged between the two ester O atoms. The implications of this peculiar conformation for the chemistry of ortho‐nitrophenyl esters in peptide synthesis are discussed. 相似文献
19.
Karl Hensen Alexander Lemke Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e565-e566
The reaction of 2‐methylpyridine with TiBr4 affords tetrabromo(2‐methylpyridine‐N)titanate(IV), C6H7Br4NTi. The environment around the Ti atom can be described as a slightly distorted trigonal bipyramid, with the nitrogen base occupying an equatorial position. The crystal structure of the title compound is isomorphous with tetrachloro(2‐methylpyridine‐N)titanate(IV). 相似文献
20.
Andrzej Gzella Urszula Wrzeciono Wolfram Pppel 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):462-466
The three title compounds, namely (Z)‐1‐(4,5‐dinitroimidazol‐1‐yl)‐3‐morpholinopropan‐2‐one 2,4‐dinitrophenylhydrazone, C16H17N9O9, (IV), (Z)‐3‐morpholino‐1‐(4‐morpholino‐5‐nitroimidazol‐1‐yl)propan‐2‐one 2,4‐dinitrophenylhydrazone, C20H25N9O8, (Va), and (E)‐3‐morpholino‐1‐(4‐morpholino‐5‐nitroimidazol‐1‐yl)propan‐2‐one 2,4‐dinitrophenylhydrazone tetrahydrofuran solvate, C20H25N9O8·C4H8O, (Vb), have been prepared and their structures determined. In (IV), the C‐4 nitro group is nearly perpendicular to the imidazole ring and the C‐4—NO2 bond length is comparable to the value for a normal single Csp2—NO2 bond. In (IV), (Va) and (Vb), the C‐5 nitro group deviates insignificantly from the imidazole plane and the C‐5—NO2 bond length is far shorter in all three compounds than C‐4—NO2 in (IV). In consequence, the C‐4 nitro group in (IV) is easily replaced by morpholine, while the C‐5 nitro group in (IV), (Va) and (Vb) shows an extraordinary stability on treatment with the amine. The E configuration in (Vb) is stabilized by a three‐centre hydrogen bond. 相似文献