共查询到20条相似文献,搜索用时 31 毫秒
1.
Erik Heigel Hans Bock Volker Krenzel Mark Sievert 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(2):154-155
The title compound, Na+·C6H5S−·C6H16N2, forms lipophilically wrapped infinite sodium chains along the a axis. Each sodium cation is coordinated by three thiophenolate S atoms and two N centres of one tetramethylethylenediamine molecule. 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.
Pierre Thuéry Martine Nierlich Jacques Vicens Bernardo Masci 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):70-71
The title compound, 7,13,21,27-tetra-tert-butyl-3,17-dioxapentacyclo[23.3.1.15,9.111,15.19,23]ditriaconta-1(29),5,7,9(30),11(31),12,14,19(32),20,22,25,27-dodecaene-29,30,31,32-tetraol, crystallizes as a solvate with one molecule of chloroform and one molecule of tetrahydrofuran, C46H60O6·CHCl3·C4H8O. The calixarene assumes a cone-like conformation stabilized by intramolecular hydrogen bonds involving both phenolic and ether O atoms. The two solvent molecules are located in each of the two half-cone cavities of the calixarene. 相似文献
4.
Jan W. Bats Marc A. Grundl A. Stephen K. Hashmi 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(2):208-210
The crystal structure of the title compound, C16H22N2O4, has two independent chiral molecules related by a pseudo-inversion centre. 14 of the 22 non-H atoms have a centrosymmetric counterpart within a tolerance of 0.17 Å. A search of the Cambridge Structural Database [Spring 2000; Allen & Kennard (1993). Chem. Des. Autom. News, 8 , 1, 31–37] shows at least 10% of the crystal structures reported in the literature with space group P21 and Z = 4 to be chiral compounds with a pseudo-P21/c packing. 相似文献
5.
Robert W. Janes Brian S. Potter Matthew A. Naylor Amanda C. Ferguson Kantilal B. Patel Michael R. L. Stratford Peter Wardman Steven A. Everett 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):58-61
1-Methylindole-3-carboxaldehyde oxime, C10H10N2O, (I),and (E)-5-methoxy-1-methylindole-3-carboxaldehyde oxime, C11H12N2O2, (II), were examined structurally to ascertain the geometry of the hydroxyimino function relative to the indole core. Oxime (I) exhibits cis geometry and there are two molecules in the asymmetric unit. In contrast, oxime (II) exhibits trans geometry and has four molecules in the asymmetric unit, with the geometry of the 5-methoxy group in one molecule differing from that in the other three. Both crystal structures are maintained by hydrogen bonding with no π-stacking of the indole moiety present. 相似文献
6.
Dorothy H. Gibson Mark S. Mashuta Haiyang He 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(10):1135-1137
The two title compounds, [Re(C10H10N6)(CO)3]Br and [Re(C11H12N6)(CO)3]I·0.5C2H6O, have slightly distorted octahedral geometries about the rhenium centers. The distortions result from the constraints of the η3-coordinated tris(pyrazol-1-yl)methane ligands in each case which reduce the N—Re—N bond angles well below the preferred value of 90° for facially disposed ligands at a six-coordinate metal center. 相似文献
7.
Alexander J. Blake Vito Lippolis Simon Parsons Martin Schröder 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):36-37
In the title complex, [CuCl2(C12H24S6)]n, the CuCl2 unit and the ligand lie on and about inversion centres, respectively. The coordination geometry at CuII is a tetragonally elongated octahedron with the equatorial positions occupied by two chlorides, Cu—Cl 2.2786 (12) Å, and two S donors, Cu—S 2.3710 (13) Å. The apical positions of the octahedron are defined by two S donors at distances of 2.8261 (14) Å from the metal. The macrocyclic ligand adopts a very puckered and distorted conformation. Eight of the 18 torsion angles are less than 90° and all S-donors are oriented exo to the ring. 相似文献
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9.
Jan Fábry Jan Kroupa Ivana Císařová 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):22-25
-Hexylammonium dihydrogenarsenate, (C6H16N)[AsO2(OH)2], and -octylammonium dihydrogenarsenate, (C8H20N)[AsO2(OH)2], are both ferroelastic at room temperature. The samples used in this study were not subjected to a phase transition after they had been crystallized. The structures are monoclinic (P21/n) and isostructural with the corresponding dihydrogenphosphates. Each sample contained two domains and each structure was refined as a twin. There are strong hydrogen bonds between dihydrogenarsenates and moderate hydrogen bonds between dihydrogenarsenates and -alkylammonium groups. The hydrogen-bond distances correspond well to those observed in the dihydrogenphosphates. All the atoms except two H atoms exist in pairs linked by the lost symmetry operations derived from the prototypic space group P2/b21/n21/a. Each of these two different H atoms is involved in an asymmetric hydrogen bond between an oxygen pair. These oxygens are supposed to change their roles as hydrogen-bond donors and acceptors during the ferroelastic switching. The phase-transition sequences are affected by interactions between the neighbouring organic chains in the structure. 相似文献
10.
Rangachari Vijayaraghavan Pravindra Kumar Sharmistha Dey Tej P. Singh 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(10):1220-1221
The structure of the title peptide, C25H27N3O5, has been determined and its conformation analysed. Values of the standard peptide torsion angles are ϕ1 = −44.2 (3)°, ψ1 = 135.9 (2)°, ϕ2 = −141.6 (2)° and ψ2T = 168.0 (2)°. The crystal structure is stabilized by an intermolecular hydrogen bond, with an N⃛O distance of 2.919 (3) Å, which is formed between screw-axis-related NH and CO groups of dehydrovaline residues. 相似文献
11.
Stefanus Otto Alfred Johannes Muller 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(12):1405-1407
The crystal structure of cis-[PtCl2(C6H15As)2], (I), is isostructural with a previously reported structure of cis-[PtCl2(C6H15P)2], (II). A new polymorph of (II) is also reported here. Selected geometrical parameters in the arsine complex are Pt—Cl 2.3412 (12) and 2.3498 (13), Pt—As 2.3563 (6) and 2.3630 (6) Å, Cl—Pt—Cl 88.74 (5), As—Pt—As 97.85 (2), and Cl—Pt—As 171.37 (4) and 177.45 (4)°. Corresponding parameters in the phosphine complex are Pt—Cl 2.364 (2) and 2.374 (2), Pt—P 2.264 (2) and 2.262 (2) Å, Cl—Pt—Cl 85.66 (9), P—Pt—P 98.39 (7), and Cl—Pt—P 170.26 (7) and 176.82 (8)°. 相似文献
12.
Robert A. Burrow David H. Farrar Alan J. Lough Márcia R. Siqueira Fatima Squizani 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):e357-e358
The crystal structure of the title compound, C6H7O2P, shows continuous hydrogen-bonding chains in the x direction, with a P—O⋯O=P distance of 2.513 (3) Å. 相似文献
13.
Geraldo L. Crossetti Carlos A. L. Filgueiras R. Alan Howie James L. Wardell Claudio M. Ziglio 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(11):1279-1281
In the title compound, [NiBr2(C31H32NP)], (I), the second reported example of a nickel–iminophosphine N,P-chelate in which the Ni atom has tetrahedral coordination, the Ni coordination is distorted as a consequence of the N—Ni—P chelate bite angle of 91.07 (6)° compensated by the Br—Ni—Br angle of 126.385 (18)°. In (I) and its analogue, viz. dichloro{[2-(4-isobutyloxazol-2-yl)phenyl]diphenylphosphine-N,P}nickel(II), the Ni—N and Ni—P distances are greater and the N—Ni—P ligand bite angles smaller than those observed in a series of related complexes with square-planar nickel. 相似文献
14.
Tuncer Hökelek Muhammed Işıklan Zeynel Kılıç 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):117-119
In the title compound, C18H17N3O2, a strong intramolecular O—H⃛N hydrogen bond [N⃛O 2.607 (3), O—H 0.97 (3) and H⃛N 1.71 (3) Å, and O—H⃛N 153 (2)°] was observed, which leads to a unique phenol–imine tautomerism in the solid state. The C=N imine bond distance and the C—N—C bond angle [1.287 (2) Å and 121.7 (1)°, respectively] indicate the existence of this phenol–imine tautomer. In solution, the phenol–imine tautomer of the title free Schiff base ligand is dominant in both polar and non-polar solvents, as supported by 1H NMR and UV–visible spectroscopic data. 相似文献
15.
Ulf Lawrentz Walter Grahn Ina Dix Peter G. Jones 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):126-128
The title compound, C34H40N2O2S2, adopts a trans conformation. The four conjugated Csp2—Csp2 single and double bonds of the polymethinic moiety, which bridges both heterocyclic end groups and the central four-membered ring, display nearly equal bond lengths. The molecule is nearly planar, with interplanar angles between the benzothiazole end groups and the central four-membered ring of 6.9 (1) and 7.7 (1)°; the angle between the heterocyclic systems is 1.8 (1)°. The crystal packing involves π-stacking effects, with intermolecular C⃛C distances varying from 3.755 (3) to 3.991 (3) Å. 相似文献
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17.
R. Alan Howie James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1041-1043
The structures of the ketotins determined here, [SnCl2(C6H11O)2] and [Sn(C3S5)(C6H11O)2], respectively, along with that previously reported for [MeC(O)CH2CMe2]2SnI2, are compared with the structures of the analogous estertins [MeOC(O)CH2CH2]2SnX2. Pairwise comparison of the mean ketotin [estertin] Sn—X and Sn—O distances as Sn—X 2.4422 (4) [2.4054 (7) Å], 2.4970 (4) [2.471 (2) Å] and 2.8463 (4) [2.7788 (8) Å] and Sn—O 2.4926 (12) [2.528 (1) Å], 2.6110 (11) [2.629 (7) Å] and 2.435 (3) [2.525 (4) Å] (for X = Cl, S and I, respectively) clearly demonstrates the superior donor ability of the ketotin O atom in chelate formation. 相似文献
18.
Miao Du Xian-He Bu He Liu Xue-Bing Leng 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(2):201-202
The crystal structure of the title compound, C16H8N6, contains two independent molecules with no significant difference in their structures. The pyrazine ring makes dihedral angles of 36.7 (2) and 36.5 (3)° with the two pyridine rings in one molecule, and 43.1 (2) and 38.4 (1)° in the other. The dihedral angles between the two pyridine rings are 58.2 (2) and 56.0 (2)°, respectively. The favoured orientation of the pyridine rings is such that their N atoms face each other. 相似文献
19.
Qingli Hao Fangfang Jian Xin Wang Ibrahim Abdul Razak S. Shanmuga Sundara Raj Hoong-Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(2):160-161
In the title compound, [Ni(C6H14O2PS2)2(C5H6N2)2], the coordination around the Ni atom, which lies on a crystallographic centre of symmetry, is octahedral with the S atoms from the dithiophosphate ligands occupying the equatorial positions, while the axial positions are occupied by the ring N atoms of the 2-aminopyridine ligands. The molecules form layers in the bc plane which are stacked in the direction of the a axis. 相似文献