Latest documents http://publikationen.stub.uni-frankfurt.de/index/index/ Wed, 11 Jan 2012 15:47:24 +0100 Wed, 11 Jan 2012 15:47:24 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27430 The title co-crystal, C9H9NO2·C6H6O2, is composed of one 2,6-diacetylpyridine molecule and one resorcinol molecule as the asymmetric unit. In the 2,6-diacetylpyridine molecule, the two carbonyl groups are antiperiplanar to the pyridine N atom. In the crystal, the 2,6-diacetylpyridine and resorcinol molecules are connected by two O-H...O hydrogen bonds, forming planar chains of alternating components running along [120]. Ton Quoc Cuong; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27430 Thu, 01 Nov 2012 15:47:24 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27429 The title compound, C23H32Cl2N2O2, a potential chiral ligand for coordination chemistry, was prepared by a two-step reaction. The molecule is located on a crystallographic centre of inversion. As a result, the methyl group bonded to the methylene group is disordered over two equally occupied positions, sharing the same site as the H atom of the chiral C atom. As a further consequence of the crystallographic centrosymmetry, the 1,2-diaminopropane unit adopts an antiperiplanar conformation and the two benzene rings are coplanar. The central chain is in an all-trans arrangement. An intramolecular O-H...N hydrogen bond makes an S(6) ring motif. A C-H...[pi] interaction links the molecules into one-dimensional chains along the [001] direction. Augusto Rivera; Dency Jose Pacheco; Jaime Ríos-Motta; Mauricio Maldonado; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27429 Thu, 01 Nov 2012 15:41:08 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27428 Chelidamic acid (4-hydroxypyridine-2,6-dicarboxylic acid) and 2,6-diaminopyridine react to form the title salt, C5H8N3+·C7H4NO5-; there are two formula units in the asymmetric unit. The pyridine N atom of 2,6-diaminopyridine is protonated whereas chelidamic acid is deprotonated at both carboxylate groups but protonated at the N atom; the reaction involves intra- and intermolecular proton transfer. In the crystal, each 2,6-diaminopyridinium cation participates in five strong N-H...O hydrogen bonds (including one bifurcated hydrogen bond). The crystal structure also features strong O-H...O hydrogen bonds between the chelidamate anions, leading to chains along the a axis. Ton Quoc Cuong; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27428 Thu, 01 Nov 2012 15:24:52 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27427 The title compound, C11H8O4, features an almost planar molecule (r.m.s. deviation = 0.033 Å for all non-H atoms). In the crystal, the molecules are linked via C-H...O hydrogen bonds, forming two-dimensional networks lying parallel to (1-21). Aamer Saeed; Aalia Ibrar; Muhammad Arshad; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27427 Thu, 01 Nov 2012 15:02:55 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27424 The crystal structure of the title compound, Na[(C6F5)BH3], is composed of discrete anions and cations. The sodium cations are surrounded by four anions with three short Na...B [2.848 (8), 2.842 (7) and 2.868 (8) Å] and two short Na...F contacts [2.348 (5) and 2.392 (5) Å], forming a three-dimensional network. The anion is the first structural example of a pentafluorophenyl ring carrying a BH3 group. Hannes Vitze; Hans-Wolfram Lerner; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/27424 Thu, 01 Nov 2012 14:54:22 +0100 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25862 In the title compound, C27H37N2 +·Cl−·2CH2Cl2, the cation and the anion are each located on a crystallographic mirror plane. Both of the dichloro­methane solvent mol­ecules show a disorder across a mirror plane over two equally occupied positions. Additionally, one isopropyl group is also disordered. In the crystal, the cations are connected to the chloride ions via C—H[cdots, three dots, centered]Cl hydrogen bonds. Matthias Berger; Norbert Auner; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25862 Tue, 28 Aug 2012 09:53:59 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25861 In the title compound, C27H37N2 +·Br−·2CH2Cl2, both the cation and the anion are located on a crystallographic mirror plane. Both of the dichloro­methane solvent mol­ecules show a disorder across a mirror plane over two equally occupied positions. In the crystal, the cations are connnected to the bromide ions via C—H[cdots, three dots, centered]Br hydrogen bonds. Matthias Berger; Norbert Auner; Tanja Sinke; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25861 Tue, 28 Aug 2012 09:26:34 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25859 Mol­ecules of the title compound (alternative name: butane-1,4-diyl dinicotinate), C16H16N2O4, lie on a inversion centre, located at the mid-point of the central C—C bond of the aliphatic chain, giving one half-mol­ecule per asymmetric unit. The butane chain adopts an all-trans conformation. The dihedral angle between the mean plane of the butane-3-carboxyl­ate group [for the non-H atoms, maximum deviation = 0.0871 (15) Å] and the pyridine ring is 10.83 (7)°. In the crystal, mol­ecules lie in planes parallel to (122). The structure features weak π–π inter­actions with a centroid–centroid distance of 3.9281 (11) Å. Javier Vallejos; Iván Brito; Alejandro Cárdenas; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25859 Tue, 28 Aug 2012 09:19:27 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25860 The crystal structure of the title compound, [Fe(C5H5)(CH3CN)(CO)2]BF4, of which only the coordinates of the non-H atoms of the cation have previously been reported [Fadel et al. (1979 [triangle]). Z. Anorg. Allg. Chem. 453, 98–106] has been redetermined. The FeII atom in the complex cation is coordinated by a cyclo­penta­dienyl ring, two carbonyl ligands and an acetonitrile mol­ecule displaying a three-legged piano stool structure. Three of the four F atoms of the BF4 − anion are disordered over two sets of sites, with a site-occupancy factor of 0.709 (10) for the major occupied site. Theresa Irene Kückmann; Hans-Wolfram Lerner; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25860 Tue, 28 Aug 2012 09:00:44 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25858 A new polymorph of the title compound, [Pd2(C8H18P)2(C8H19P)2], has been found. It belongs to the triclinic P-1 space group, whereas the known form [Leoni, Sommovigo, Pasquali, Sabatino & Braga (1992 [triangle]), J. Organo­met. Chem. 423, 263–270] crystallizes in the monoclinic C2/c space group. The title compound features a dinuclear palladium complex with a planar central Pd2(μ-P)2 core (r.m.s. deviation = 0.003 Å). The Pd—Pd distance of 2.5988 (5) Å is within the range of a PdI—PdI bond. The mol­ecules of both polymorphs are located on a crystallographic centre of inversion. The mol­ecular conformations of the two polymorphs are essentially identical. The crystal packing patterns, on the other hand, are slightly different. Jens Breunig; Hans-Wolfram Lerner; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25858 Tue, 28 Aug 2012 08:26:52 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/24584 Large crystals of the methyl ester of the N-a-benzyloxycarbonyl protected Ala-Phe dipeptide (Z-AF-OMe) were obtained after the very slow evaporation of a solution of the corresponding carboxylic acid (Z-AF-OH) in methanol containing an excess of HCl. The structure was confirmed by single crystal X-ray diffraction data. It crystallizes in the orthorhombic space group P212121 with unit cell dimensions a = 5.0655(6) Å, b = 8.4614(8) Å, c = 46.856(5) Å, V = 2008.3(4) Å3, Z = 4. In the crystal, the molecules form hydrogen bonded chains running along the a axis of the unit cell. Other secondary interactions are also discussed. Ignacio Alfonso; Michael Bolte; M. Isabel Burguete; Santiago V. Luis article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/24584 Fri, 29 Jun 2012 09:59:54 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25267 Two tetrahydroisoquinoline alkaloids were extracted from the alkaloid fraction of a methanol extract of the seeds of Calycotome Villosa Subsp. intermedia. Their structures were established as (R)-1-hydroxymethyl-7-8-dimethoxy-1,2,3,4-tetrahydro- isoquinoline (1) and (S)-7-hydroxymethyl-2-3-dimethoxy-7,8,9,10-tetrahydroisoquinoline chloride (2) by spectroscopic techniques and X-ray diffraction analysis. Ali El Antri; Ibtissam Messouri; Mohamed Bouktaib; Rachid El Alami; Michael Bolte; Brahim El Bali; Mohammed Lachkar article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25267 Wed, 27 Jun 2012 14:01:17 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25268 The title thiourea was synthesized by reaction of 3,4,5-trimethoxybenzoyl isothiocyante with 3-fluoroaniline. The 3,4,5-trimethoxybenzoyl isothiocyante was produced in situ by reaction of 3,4,5-trimethoxybenzoyl chloride with ammonium thiocyanate in dry acetonitrile. The structure was confirmed by the spectroscopic, elemental analysis and single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 13.0966(9), b = 16.6460(13), c = 7.8448(5), β = 106.721(5)°, V 1637.9(2) ų, Z = 4. Aamer Saeed; Uzma Shaheen; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25268 Wed, 27 Jun 2012 13:46:58 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25300 Mol-ecules of the title compound, [Zn(8)(C(6)F(5))(8)O(4)(C(4)H(10)O)(4)], are located on a special position of site symmetry [Formula: see text]. As a result, there is just one quarter-mol-ecule in the asymmetric unit. The title compound features a Zn(4)O(4) cube. Each Zn atom in the cube carries a pentafluorophenyl substituent. Each O atom is bonded to a further Zn atom, which is connected to a pentafluorophenyl substituent and the O atom of a diethyl ether mol-ecule. All ether C atoms are disordered over two sets of sites with a site occupation factor of 0.51 (2) for the major occupied site. Daniel Franz; Hans-Wolfram Lerner; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25300 Wed, 27 Jun 2012 12:56:10 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25303 Mol­ecules of the title compound, C20H14O2, show approximate C s symmetry with the approximate mirror plane perpendicular to the central ring. The torsion angles about the acyclic bonds are 30.05 (15) and 30.77 (15)° in one half compared to −36.62 (14) and −18.60 (15)° in the other half of the mol­ecule. The central aromatic ring makes dihedral angles of 47.78 (4) and 51.68 (3)° with the two terminal rings. Ahmed Raza Ahsraf; Zareen Akhter; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25303 Wed, 27 Jun 2012 12:42:31 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25302 The title compound, C14H20O5S·0.5H2O, crystallizes with two organic mol­ecules and a solvent water mol­ecule in the asymmetric unit. In both mol­ecules, the hexa­pyranosyl rings adopt a slightly distorted chair conformation (5 C 2) with four substituents in equatorial positions and one substituent in an axial position. The main difference between the organic mol­ecules is the dihedral angle between the phenyl ring and the best plane defined by the O—C1—C2—C3 atoms (r.m.s deviations = 0.003 and 0.043 Å) of the hexa­pyranosyl rings [47.4 (4) and 86.5 (4)°]. In the asymmetric unit, mol­ecules are linked by two strong O—H[cdots, three dots, centered]O hydrogen bonds. In the crystal, the components are linked by a total of 10 distinct O—H[cdots, three dots, centered]O hydrogen bonds, resulting in the formation of a two-dimensional network parallel to the ab plane. Iván Brito; László Szilágyi ; Ambati Ashok Kumar; Joselyn Albanez; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25302 Wed, 27 Jun 2012 12:35:24 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/22381 The title compound, C15H15BrO2, was synthesized by a Brønsted acid-catalysed domino electrocyclization-halogenation reaction. The five-membered ring is essentially planar (r.m.s. deviation 0.006 Å) and forms a dihedral angle of 72.7 (3)° with the attached phenyl ring. The six-membered heterocycle adopts a half-chair conformation. The crystal packing is stabilized by a C—H[cdots, three dots, centered]O contact. Winai Ieawsuwan; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/22381 Wed, 27 Jun 2012 12:24:57 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25299 The title compound, C(21)H(18)ClN, was synthesized by an enanti-oselective Brønsted acid-catalysed transfer hydrogenation reaction. The six-membered heterocycle adopts a half-chair conformation. It has the biphenyl residue in an axial position. The two rings of the biphenyl residue are almost coplanar [dihedral angle = 2.65 (9)°]. The crystal packing is stabilized by N-H⋯Cl hydrogen bonds, which connect the mol-ecules into chains running along the a axis. Thomas Theissmann; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25299 Wed, 27 Jun 2012 10:23:16 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25298 The title compound, C25H20N4O2, is a ditopic ortho-hydro­quinone-based bis­(pyrazol-1-yl)methane ligand. The dihedral angles between the planes of the pyrazole rings and their attached phenyl rings are 17.4 (3) and 5.9 (4)°. The pyrazole rings make a dihedral angle of 87.84 (16)°. One of the two hy­droxy groups forms an intra­molecular hydrogen bond to the other hy­droxy group, whereas the second is involved in an inter­molecular O—H[cdots, three dots, centered]N hydrogen bond. As a result of these inter­molecular hydrogen bonds, helical chains running along the b axis are formed. Florian Blasberg; Hans-Wolfram Lerner; Michael Bolte article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25298 Wed, 27 Jun 2012 10:04:29 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25292 The fused five- and six-membered rings in the title compound, C14H12N2O, are essentially planar, the largest deviation from the mean plane being 0.023 (2) Å. The dihedral angle between the benzimidazole mean plane and the phenyl ring is 68.50 (6)°. In the crystal, each mol­ecule is linked to its symmetry equivalent created by a crystallographic inversion center by pairs of N—H[cdots, three dots, centered]O hydrogen bonds, forming inversion dimers. Younes Ouzidan; El Mokhtar Essassi; Santiago V. Luis; Michael Bolte; Lahcen El Ammari article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25292 Mon, 25 Jun 2012 16:40:58 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25291 In the mol-ecule of the title compound, C(12)H(12)BrN(3)O, the fused-ring system is essentially planar, the largest deviation from the mean plane being 0.0148 (3) Å. The two allyl groups are nearly perpendicular to the imidazo[4,5-b]pyridine plane [C-C-N-C torsion angles of 81.6 (4) and -77.2 (4)°] and point in the same direction. The planes through the atoms forming each allyl group are nearly perpendicular to the imidazo[4,5-b]pyridin-2-one system, as indicated by the dihedral angles between them of 80.8 (5) and 73.6 (5)°. Siham Dahmani; Youssef Kandri Rodi; Santiago V. Luis; Michael Bolte; Lahcen El Ammari article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25291 Mon, 25 Jun 2012 16:30:23 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25290 The two fused five- and six-membered rings building the mol­ecule of the title compound, C13H10BrN3, are approximately planar, the largest deviation from the mean plane being 0.004 (2) Å. The dihedral angle between the imidazo[4,5-b]pyridine mean plane and that of the phenyl ring is 41.84 (11)°. The structure is held together by slipped π–π stacking between symmetry-related mol­ecules, with an inter­planar distance of 3.583 (1) Å and a centroid–centroid vector of 3.670 (2) Å. Younes Ouzidan; El Mokhtar Essassi; Santiago V. Luis; Michael Bolte; Lahcen El Ammari article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25290 Mon, 25 Jun 2012 16:24:16 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25289 The structure of the title compound, (C15H15N2O4)[AgI2], consists of an organic 4-[3-(isonicotino­yloxy)propoxycarbon­yl]pyridinium cation which has a gauche–gauche (O/C/C/C—O/C/C/C or GG’) conformation and lies on a twofold rotation axis, which passes through the central C atom of the aliphatic chain, and an inorganic [AgI2]− anion. In the complex anion, the Ag+ cation is bound to two I− anions in a linear geometry. The anion was modelled assuming disorder around a crystallographic inversion centre near the location of the Ag+ cation. The crystal packing is stabilized by a strong inter­molecular N—H[cdots, three dots, centered]N hydrogen bond, which links the cations into zigzag chains with graph-set notation C(16) running along the face diagonal of the ac plane. The N-bound H atom is disordered over two equally occupied symmetry-equivalent sites, so that the mol­ecule has a pyridinium ring at one end and a pyridine ring at the other. Javier Vallejos; Iván Brito; Alejandro Cárdenas; Michael Bolte; Matías López-Rodríguez article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25289 Mon, 25 Jun 2012 15:07:47 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25288 In the mol­ecular structure of the title compound, C21H18N2O, the fused-ring system is essentially planar, the largest deviation from the mean plane being 0.0121 (9) Å. The O atom and adjacent C atom are located in Wyckoff position 4e on a twofold axis (0, y, 1/4). The two benzyl groups are almost perpendicular to the benzimidazole plane, but point in opposite directions. The dihedral angle between the benzimidazole mean plane and the phenyl ring is 81.95 (5)°, whereas that between the two benzyl groups is 60.96 (7)°. Youssef Kandri Rodi; Fouad Ouazzani Chahdi; El Mokhtar Essassi; Santiago V. Luis; Michael Bolte; Lahcen El Ammari article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25288 Mon, 25 Jun 2012 14:56:36 +0200 http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25287 The asymmetric unit of the title compound, C16H23ClN2O, comtains two independent mol­ecules in which the fused-ring systems are essentially planar, the largest deviation from the mean plane of each mol­ecule being 0.011 (2) Å and 0.016 (2) Å. The benzimidazole rings of the two mol­ecules make a dihedral angle of 66.65 (7)°. The nonyl substituents are almost perpendicular to the benzimidazole planes [C—N—C—C tosrsion angles = 96.0 (3) and 81.0 (2)°]. In the crystal, each independent molecule forms an inversion dimer via a pair of N—H[cdots, three dots, centered]O hydrogen bonds. In one of the independent molecules, the terminal –CH2–CH3 group of the alkyl chain is disordered over two sets of sites with a refined occupancy ratio of 0.746 (7):0.254 (7). Youssef Kandri Rodi; Fouad Ouazzani Chahdi; El Mokhtar Essassi; Santiago V. Luis; Michael Bolte; Lahcen El Ammari article http://publikationen.stub.uni-frankfurt.de/frontdoor/index/index/docId/25287 Mon, 25 Jun 2012 14:48:25 +0200