Acta crystallographica. Section C, Crystal structure communications最新文献

2,4-Dinitro-N-(2-phenylethyl)aniline, C14H13N3O4, (I), crystallizes with one independent molecule in the asymmetric unit. The adjacent amine and nitro groups form an intramolecular N-H...O hydrogen bond. The anti conformation about the ethyl C-C bond leads to the phenyl and aniline rings being essentially parallel. Molecules are linked into dimers by intermolecular N-H...O hydrogen bonds, such that each amine H atom participates in a three-centre interaction with two nitro O atoms. Though the dimers pack so that the arene rings of adjacent molecules are parallel, the rings are staggered and π-π interactions do not appear to be favoured. 4,6-Dinitro-N,N'-bis(2-phenylethyl)benzene-1,3-diamine, C22H22N4O4, (II), differs from (I) in the presence of a second 2-phenylethylamine group on the substituted ring. Compound (II) also crystallizes with one unique molecule in the asymmetric unit. Both amine groups are involved in intramolecular N-H...O hydrogen bonds with adjacent nitro groups. Although one ethyl group adopts an anti conformation as in (I), the other is gauche, with the result that the pendant phenyl rings are not parallel. The amine group that is part of the gauche conformation participates in a three-centre N-H...O hydrogen bond with the nitro group of a neighbouring molecule, leading to dimers as in (I). The other amine H atom does not form any intermolecular hydrogen bonds. The packing leads to separations of ca 3.4 Å of the parallel anti phenyl and aminobenzene rings. 2-Cyano-4-nitro-N-(2-phenylethyl)aniline, C15H13N3O2, (III), differs from (I) only in having a cyano group in place of the 2-nitro group. The absence of the adjacent nitro group eliminates the intramolecular N-H...O hydrogen bond. Molecules of (III) adopt the same anti conformation about the ethyl group as in (I), but crystallize in the higher-symmetry monoclinic space group P21/n. The molecules are linked into dimers via N-H...N amine-cyano hydrogen bonds, while the nitro groups are not involved in any N-H...O interactions. Owing to the different symmetry, the molecules pack in a herringbone pattern with fewer face-to-face interactions between the rings. The closest such interactions are about 3.5 Å between rings that are largely slipped past one another. 4-Methylsulfonyl-2-nitro-N-(2-phenylethyl)aniline, C15H16N2O4S, (IV), differs from (I) in having a methylsulfonyl group in place of the 4-nitro group. The intramolecular N-H...O hydrogen bond is present as in (I). However, unlike (I), the conformation about the ethyl group is gauche, so the two arene rings are nearly perpendicular rather than parallel. The packing is significantly different from the other three structures in that there are no intermolecular hydrogen bonds involving the N-H groups. The molecules are arranged in tetragonal columns running along the c axis, with the aniline rings mostly parallel and separated by ca 3.7 Å. Taken together, these structures demonstrate that modest changes in functional grou

The identity of the major product of Ru-catalysed alkene metathesis of two polyene substrates has been determined using density functional theory (DFT) NMR prediction, a (1)H-(1)H Total Correlated Spectroscopy (TOCSY) NMR experiment and ultimately by single-crystal X-ray crystallography. The substrates were designed as those that would potentially allow expedient access to the trans-decalin skeleton of the natural product (-)-euonyminol, but the product was found to be a bis-cyclopentenyl-β-cyanohydrin [1-(1-hydroxycyclopent-3-en-1-yl)cyclopent-3-ene-1-carbonitrile, C11H13NO] rather than the trans-2,3,6,7-dehydrodecalin-β-cyanohydrin.

In the crystal structure of the title organic-inorganic hybrid material, (C10H22N2)[ZnCl4], the tetrachloridozincate anions and 1-cyclohexylpiperazine-1,4-diium dications are interconnected via N-H...Cl and C-H...Cl hydrogen bonds to form layers parallel to the (001) plane. The cyclohexyl groups from adjacent chains interdigitate, thus building the three-dimensional structure. The piperazinium and cyclohexyl rings exhibit regular spatial chair conformations. The title salt was also characterized by FT-IR and Raman spectroscopic analyses.

The novel cadmium complex catena-poly[cadmium(II)-μ3-{2-[3-(pyridin-2-yl)-1H-pyrazol-1-yl]butanedioato}], [Cd(C12H9N3O4)]n, has been prepared by the conjugate addition reaction of 2-(1H-pyrazol-3-yl)pyridine to fumaric acid in the presence of Cd(OAc)2·3H2O (OAc is acetate) at 413 K. Single-crystal X-ray diffraction analysis reveals that the complex consists of one-dimensional ladders constructed from [Cd2(COO)2] dimeric subunits. A combination of hydrogen bonding and π-π stacking interactions extend the one-dimensional ladders into a three-dimensional supramolecular architecture.

Two new inorganic-organic coordination polymers, namely poly[[μ6-2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetato][μ4-2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetato]disodium(I)], [Na2(C19H19O6)2]n, (I), and poly[hexa-μ-aqua-diaquabis{μ3-2,2'-[sulfonylbis(1,4-phenyleneoxy)]diacetato}tetrasodium(I)], [Na4(C16H14O8)2(H2O)8]n, (II), have been prepared. In (I), the asymmetric unit contains two Na(I) cations and two 2-(4-{1-[4-(carboxymethoxy)phenyl]-1-methylethyl}phenoxy)acetate (HL1(-)) ligands. Each Na(I) cation is octahedrally coordinated by two ether O atoms and four carboxylate O atoms of three different HL1(-) ligands. The NaO6 polyhedra share edges to form an inorganic ribbon along the a axis. These inorganic ribbons are further connected by the HL1(-) ligands to generate two-dimensional layers parallel to the (001) plane. The structure of (II) consists of ribbons of four crystallographically independent Na atoms (three six- and one five-coordinate), which are bridged by carboxylate O atoms of 4,4'-[sulfonylbis(1,4-phenyleneoxy)]diacetate (L2(2-)) ligands and water molecules. These ribbons are interlinked by L2(2-) ligands through two different coordination modes to afford a three-dimensional network.

catena-Poly[[[4-amino-N-(quinoxalin-2-yl)benzenesulfonamidato]aquacadmium(II)]-μ-4-amino-N-(quinoxalin-2-yl)benzenesulfonamidato], [Cd(C14H11N4O2S)2(H2O)], has been synthesized hydrothermally and characterized by single-crystal X-ray diffraction, elemental analysis, fluorescence, IR and thermal analysis. Single-crystal X-ray analysis reveals that the complex is a one-dimensional zigzag chain structure, and the Cd(II) cation has a distorted octahedral coordination geometry formed by five N atoms from three different sulfaquinoxaline ligands and one O atom from a water molecule. The fluorescence spectrum reveals that the complex emits strong blue fluorescence and thermal analysis shows that the complex has high thermal stability.

Solving pharmaceutical crystal structures from powder diffraction data is discussed in terms of the methodologies that have been applied and the complexity of the structures that have been solved. The principles underlying these methodologies are summarized and representative examples of polymorph, solvate, salt and cocrystal structure solutions are provided, together with examples of some particularly challenging structure determinations.

The molecular and supramolecular structures are reported of N-[2-(pyridin-2-yl)ethyl]methanesulfonamide, C8H12N2O2S, (I), N-[2-(pyridin-2-yl)ethyl]benzenesulfonamide, C13H14N2O2S, (II), and N-[2-(pyridin-2-yl)ethyl]toluenesulfonamide, C14H16N2O2S, (III). Although (II) and (III) are almost structurally identical, the N(amide)-C(ethyl)-C(ethyl)-C(pyridinyl) torsion angles for (I) and (II) are more closely comparable, with magnitudes of 175.37 (15)° for (I) and 169.04 (19)° for (II). This angle decreases dramatically with an additional methyl group in the para position of the sulfonamide substituent, resulting in a value of 62.9 (2)° for (III). In each of the three compounds there is an N-H...N hydrogen bond between the sulfonamide of one molecule and the pyridine N atom of a neighbor. Compound (I) forms hydrogen-bonded dimers, (II) uses its hydrogen bonding to connect supramolecular layers, and the hydrogen bonding of (III) connects linear chains to form layers. For arene-substituted (II) and (III), the different conformations afforded by the variable dihedral angles promote intermolecular π-π stacking in the benzene-substituted structure (II), but distorted intramolecular T-shaped π-stacking in the toluene-substituted structure (III), with a centroid-to-centroid distance of 4.9296 (10) Å.

Diffraction results obtained at 100 and 291 K, the former at high resolution, are reported for the title compound, [Cu(C10H9N4O2S)2(NH3)2] or [Cu(sulfa)2(NH3)2] [Hsulfa is 4-amino-N-(pyrimidin-2-yl)benzenesulfonamide]. The Cu(II) cation is coordinated by two N-atom donors from a bidentate sulfa ligand, by two ammonia molecules in the equatorial plane and by a monohapto (η(1)) sulfadiazine at the apex of a distorted square pyramid. The present interpretation and two earlier reports [Brown, Cook & Sengier (1987). Acta Cryst. C43, 2332-2334; Tommasino, Renaud, Luneau & Pilet (2011). Polyhedron, 30, 1663-1670] disagree about the nature and geometry of the ligands. The relationship between the present result and the former is discussed, and evidence is provided that the latter erroneously assigned an ammine as an aqua ligand.

μ-1,2-Bis(pyridin-3-yloxy)ethane-κ(2)N:N'-bis[aqua(pyridine-2,6-dicarboxylato-κ(3)O(2),N,O(6))copper(II)] tetrahydrate, [Cu2(C7H3NO4)2(C12H12N2O2)(H2O)2]·4H2O, (I), is a C-shaped molecule based on 1,2-bis(pyridin-3-yloxy)ethane (L) and Cu(II) in the presence of pyridine-2,6-dicarboxylic acid (H2pydc). The two five-coordinated Cu(II) centres are chelated by terminal pydc(2-) ligands and bridged by an L spacer. The molecules are arranged in a two-dimensional sheet via 15 O-H...O hydrogen bonds, and C-H...O interactions further bridge neighbouring sheets into a three-dimensional supermolecular architecture. The structure includes a well-resolved cyclic water tetramer, which acts as a subunit to form a larger aggregate. A thermogravimetric analysis of complex (I) was also carried out.