Showing papers in "Acta Crystallographica Section E-structure Reports Online in 2001"
TL;DR: The title compound, C4H4N6O5, crystallizes in the monoclinic space group P21/n, and is an energetic compound containing only C, H, N, and O with a density of 1.919mgm−3 as mentioned in this paper.
Abstract: The title compound, C4H4N6O5, crystallizes in the monoclinic space group P21/n, and is an energetic compound containing only C, H, N, and O with a density of 1.919 Mg m−3. Among other reasons, this remarkably high density is attributed to an extensive system of intra- and intermolecular hydrogen bonds which results in a packing scheme involving zigzag sheets.
43 citations
TL;DR: The crystal structure of hexagonal LuMnO3 at room temperature is isomorphous with YMnNO3 and deviates in important details from the early work of Yakel et al. as discussed by the authors.
Abstract: The crystal structure of hexagonal LuMnO3 at room temperature is isomorphous with YMnO3 and deviates in important details from the early work of Yakel et al. [Acta Cryst. (1963), 16, 957–962]. Mn is near the centre of its oxygen coordination environment. On the threefold axes, the apical O—Lu bonds have alternating long and short bond lengths, leading to ferroelectric behaviour. The sample studied was composed of almost equal volumes of inversion twins.
39 citations
TL;DR: In the crystal structure of the title compound, 3,4,5-tri-hydroxy-benzoic acid monohydrate, C7H6O5·H2O, the gallic acid molcule is essentially planar and has two intramolecular hydrogen bonds between hydroxyl groups.
Abstract: In the crystal structure of the title compound, 3,4,5-trihydroxybenzoic acid monohydrate, C7H6O5·H2O, the gallic acid molecule is essentially planar and has two intramolecular hydrogen bonds between hydroxyl groups. The H atoms of the three hydroxyl groups are oriented in the same direction around the ring, and form intra- and intermolecular hydrogen bonds. The crystal structure is stabilized by all available intermolecular hydrogen bonds, including also those involving the water molecule.
27 citations
[...]
TL;DR: In this paper, a head-to-tail hydrogen bond was observed between the amino acid molcules in the C3H8NO2+·C4H3O4− compound.
Abstract: In the title compound, C3H8NO2+·C4H3O4−, the alanine molecule exists in the cationic form and the maleic acid molecule in the mono-ionized state. A head-to-tail hydrogen bond is observed between the amino acid molecules. There are no direct hydrogen-bonded interactions between the semimaleate anions. The overall aggregation pattern is similar to that observed in the l-alanine-oxalic acid complex.
26 citations
TL;DR: The crystal structure of a new ternary borate, lead gallium boron tetraoxide, PbGaBO4, has been determined by X-ray diffraction using a single-crystal grown from a PbO flux.
Abstract: The crystal structure of a new ternary borate, lead gallium boron tetraoxide, PbGaBO4, has been determined by X-ray diffraction using a single-crystal grown from a PbO flux. The structure consists of infinite [010] chains of edge-sharing GaO6 octahedra bridged by BO3 triangles. The Pb2+ cations and their stereoactive lone pair occupy the apex of PbO4 square pyramids. The structure represents a new structure-type for anhydrous orthoborates. Bond-valence analysis reveals the presence of strain within the octahedral chains.
24 citations
TL;DR: The crystal structure of hexagonal ytterbium manganese oxide, YbMnO3, has been refined at room temperature as mentioned in this paper, and it is isomorphous with YMnNO3.
Abstract: The crystal structure of hexagonal ytterbium manganese oxide, YbMnO3, has been refined at room temperature. It is isomorphous with YMnO3. The Mn ions lie near the centre of a trigonal bipyramid. Although the Yb ions lie on threefold axes, the apical oxygen ions are at dissimilar distances, leading to ferroelectric behaviour. The sample studied was composed of almost an equal volume of inversion twins.
23 citations
TL;DR: AlH2(C29H41N2) as mentioned in this paper is an example of a sterically encumbered monomeric primary alane and the N-Al distance is 1.8989
Abstract: The title compound, [AlH2(C29H41N2)], is an example of a sterically encumbered monomeric primary alane. The bond lengths are within normal ranges. The N—Al distance is 1.8989 (12) A. The H atoms bonded to the aluminium center were located in a difference map and refined to Al—H distances of 1.51 (2) and 1.518 (19) A. There are no significant intermolecular interactions.
19 citations
TL;DR: The structure of the title compound, C19H18N2O, was studied in the course of their investigations on organic non-linear optical (NLO) materials as mentioned in this paper, and its molcellule with the exception of the C(CH3)2 group is nearly planar.
Abstract: The structure of the title compound, C19H18N2O, was studied in the course of our investigations on organic non-linear optical (NLO) materials. Its molecule with the exception of the C(CH3)2 group is nearly planar.
18 citations
TL;DR: In this article, the carboxyl group of the hydrogen glutarate ion makes a hydrogen-bonding pattern with N-H groups of the trimethoprim cation, which is similar to the caroxyl-carboxyl-ate group (of Asp-27 of DHFR)-trimethopric cation interaction observed in trimETHoprim-DHFR complexes.
Abstract: In the title compound, C14H19N4O3+·C5H7O4−, trimethoprim (TMP) is protonated. In the glutarate anion, one of the two carboxylic acid groups is deprotonated while the other exists as —COOH. The carboxyl group of the hydrogen glutarate ion makes a hydrogen-bonding pattern with N—H groups of the trimethoprim cation which is similar to the carboxylate group (of Asp-27 of DHFR)-trimethoprim cation interaction observed in trimethoprim–DHFR complexes. Two TMP cations and two hydrogen glutarate anions are arranged about an inversion center so that complementary DDAA arrays of quadruple hydrogen-bonding patterns are formed. The hydrogen glutarate ion bridges the 2-amino and 4-amino groups of TMP. There are also carboxyl–carboxylate hydrogen-bonding interactions involving a head-to-tail arrangement of hydrogen glutarate ions which leads to hydrogen-bonded supramolecular ribbons.
16 citations
TL;DR: Li+·CF3SO3− has already been investigated by powder diffraction methods as mentioned in this paper, and the single-crystal structure of Li+CF3 SO3− was shown to be in good agreement with the previous structure determination.
Abstract: The title compound, Li+·CF3SO3−, has already been investigated by powder diffraction methods. We present in this work the single-crystal structure, which is in good agreement with the previous structure determination.
15 citations
TL;DR: In the title compound, C9H12NO2+·C4H3O4−, the amino acid molecule exists in the cationic form and the maleic acid molcule in the mono-ionized state.
Abstract: In the title compound, C9H12NO2+·C4H3O4−, the amino acid molecule exists in the cationic form and the maleic acid molecule in the mono-ionized state. In the semi-maleate anion, a nearly symmetric intramolecular O—H⋯O hydrogen bond is observed. The aggregation pattern observed in the title crystal has striking similarities with those observed in l-phenylalanine l-phenylalaninium formate and l-phenylalanine l-phenylalaninium perchlorate.
TL;DR: The structure of the title compound, C21H19N3 (BIP1), has been determined as mentioned in this paper, which lies on a crystallographic mirror plane and the terminal phenyl groups are rotated 60.2°(2)° from the plane of the ethyl-idene-pyridine system.
Abstract: The structure of the title compound, C21H19N3 (BIP1), has been determined. The molecule lies on a crystallographic mirror plane. The terminal phenyl groups are rotated 60.2 (2)° from the plane of the ethylidenepyridine system.
TL;DR: The X-ray crystal structure of 2,5-furan-dione (C4H2O3) was determined at 130'2' K as discussed by the authors, which is the standard.
Abstract: The X-ray crystal structure of the title compound (2,5-furandione), C4H2O3, was redetermined at 130 (2) K. The C=C double bond, previously reported to be unusually short, was accurately measured as 1.3322 (9) A and thus proved to be fairly standard. The relatively high melting point of the compound is attributed to the intermolecular dipole–dipole interactions between carbonyl groups.
TL;DR: The ionic title complex was obtained by oxidation of the aryl-ytterbium(II) iodide DppYbI(thf)3 (Dpp = 2,6-Ph2C6H3) with neo-pentyl iodide.
Abstract: The ionic title complex, [YbI2(thf)5][YbI4(thf)2], was obtained by oxidation of the arylytterbium(II) iodide DppYbI(thf)3 (Dpp = 2,6-Ph2C6H3) with neopentyl iodide. In the pentagonal-bipyramidal coordinated cation [Yb—I = 2.9366 (9) A and Yb–O = 2.340 (6), 2.347 (8) and 2.365 (6) A], a twofold rotation axis passes through the Yb atom, the O atom and the midpoint of the C—C bond of one of the thf ligands. The centrosymmetric anion shows an almost regular coordination octahedron [Yb—I = 2.9641 (8) and 2.9856 (9) A, and Yb—O 2.279 (6) A].
TL;DR: Tetrasodium tricarbonatodioxouranate (VI), Na4[UO2(CO3)3), crystallizes in the trigonal space group P\overline 3c1.
Abstract: Tetrasodium tricarbonatodioxouranate(VI), Na4[UO2(CO3)3], crystallizes in the trigonal space group P\overline 3c1. Though the symmetry differs from other similar compounds (e.g. the NH4+, K+ and Tl+ salts) which are monoclinic, there is a common structure motif consisting of UO2(CO3)3 groups with a trigonal outline when viewed along the shortest O—U—O bond pair. In Na4[UO2(CO3)3], there are three non-equivalent Na atoms; Na1 (site symmetry \overline 3) and Na2 (site symmetry 3) are in centres of face-sharing octahedra, which form a chain running parallel to the c axis at each unit-cell corner, whereas the Na3 atom is surrounded by a deformed square pyramid of O atoms, forming edge-sharing triplets. The title compound has also a natural dimorph, namely the recently approved triclinic mineral cejkaite.
TL;DR: In this article, a strong symmetric O-H⋯O hydrogen bond was constructed for 2C3H7NO2 with a distance of 2.467°(2)°A.
Abstract: In the title compound, 2C3H7NO2.H+·NO3−, both the alanine residues, related by a center of symmetry, are linked by a strong symmetric O—H⋯O hydrogen bond with an O⋯O distance of 2.467 (2) A. The N atom and one of the O atoms of the nitrate anion lie on the twofold axis.
TL;DR: In this paper, the coordination polyhedron of the Cu atom is an elongated square bipyramid with \overline 1 site symmetry, which plays the role of non-symmetrical bridges responsible for formation of layers parallel to the bc plane.
Abstract: In the title compound, [CuCl2(C3H5N7)2], the coordination polyhedron of the Cu atom is an elongated square bipyramid with \overline 1 site symmetry. The equatorial positions are occupied by the two Cl atoms with Cu—Cl distances of 2.288 (1) A and two azidoethyltetrazole ligands with Cu—N distances of 1.999 (2) A. Two Cl atoms in axial positions are 2.956 (1) A distant from the Cu atom. The Cl atoms play the role of non-symmetrical bridges responsible for formation of layers parallel to the bc plane.
[...]
TL;DR: In this paper, the alanine and oxalic acid in C3H8NO2+·C2HO4− have been characterized by the presence of a C-H⋯O hydrogen bond and a short C⋮O contact between amino acids.
Abstract: In the title compound, C3H8NO2+·C2HO4−, the alanine molecule exists in the protonated cationic form and the oxalic acid molecule in the mono-ionized state. The alanine molecules dimerize across inversion centres through head-to-tail N—H⋯O hydrogen bonds. The semi-oxalate ions aggregate into hydrogen-bonded strings along the shortest cell axis. The crystal structure is also characterized by the presence of a C—H⋯O hydrogen bond and a short C⋯O contact between amino acids.
TL;DR: The title compound, C16H36N+H2PO4−1.33CH2Cl2, exists as infinite one-dimensional dihydrogen phosphate chains within cationic tetrabutyl ammonium channels as mentioned in this paper.
Abstract: The title compound, C16H36N+.H2PO4−.1.33CH2Cl2, exists as infinite one-dimensional dihydrogen phosphate chains within cationic tetrabutylammonium channels.
TL;DR: In the crystal structure of the title compound, [CuII{N(CN)2}2(C5H5NO)2] as mentioned in this paper, the geometry around the copper(II) ion is distorted square pyramidal, with the basal plane formed by the N atoms of two 3-hydroxy pyridine molecules, one N atom of a bidentate dicyanamide anion, and one n atom of monodentate di-nodesamide anions, forming a one-dimensional polymeric chain.
Abstract: In the crystal structure of the title compound, [CuII{N(CN)2}2(C5H5NO)2], the geometry around the copper(II) ion is distorted square pyramidal, with the basal plane formed by the N atoms of two 3-hydroxypyridine molecules, one N atom of a bidentate dicyanamide anion and one N atom of a monodentate dicyanamide anion. The apical position is occupied by an N atom of a bidentate dicyanamide anion, forming a one-dimensional polymeric chain.
TL;DR: In this article, the conformation of N6-benzyl-adenine hydrobromide was compared with other cytokinins, and it was shown that protonation of benzyladenine does not affect the conformational requirements for cytokinin activity.
Abstract: In the title compound, N6-benzyladenine hydrobromide [N6-benzyladeninium bromide], C12H12N5+·Br−, the adenine moiety exists as the N3-protonated N7-H tautomer. The N6 substituent is distal to N7 and the phenyl ring makes a dihedral angle of 108.43 (12)° with the adenine plane. Thus, protonation of benzyladenine does not affect the conformational requirements for cytokinin activity. The conformation of the title compound has been compared with other cytokinins.
[...]
TL;DR: The single crystal of the title compound, C8H8, was obtained by in situ crystallization as mentioned in this paper, and the torsion angle between the phenyl ring and the vinyl group is 7.82°(17)°.
Abstract: The single crystal of the title compound, C8H8, was obtained by in situ crystallization. The torsion angle between the phenyl ring and the vinyl group is 7.82 (17)°. The double-bond length in the vinyl group is 1.3245 (16) A, which is slightly shorter than a normal C=C double bond.
TL;DR: The title complex [NiCl2(bipy)2] consists of an Ni atom coordinated to two cis chlorides and two bidentate bi-pyridines as discussed by the authors.
Abstract: The title complex, [NiCl2(bipy)2].CH3OH, where bipy is 2,2-bipyridine (C10H8N2), consists of an Ni atom coordinated to two cis chlorides and two bidentate bipyridines. One molecule of methanol is hydrogen bonded to one of the two inequivalent chlorides.
TL;DR: In this paper, the title compound, C4H12N+·I5−, consists of V-shaped I5− ions which are linked to adjacent I5 − ions to form a flat square mesh normal to (001), with four I atoms on each edge.
Abstract: The title compound, C4H12N+·I5−, consists of V-shaped I5− ions which are linked to adjacent I5− ions to form a flat square mesh normal to (001), with four I atoms on each edge. The tetramethylammonium ions are located at the centre of each square.
TL;DR: The crystal structure of doxylamine hydrogen succinate, C17H23N2O+·C4H5O4−, contains two independent protonated molecules of doylamine with different conformations and two succinate anions in an asymmetric unit as discussed by the authors.
Abstract: The crystal structure of doxylamine hydrogen succinate or dimethyl{[1-phenyl-1-(2-pyridyl)ethoxy]ethyl]ammonium hydrogen succinate, C17H23N2O+·C4H5O4−, contains two independent protonated molecules of doxylamine with different conformations and two succinate anions in an asymmetric unit. The structure is stabilized by hydrogen bonds involving the cations and the anions, with O⋯O and N⋯O distances in the range 2.536 (5)–2.853 (5) A.
TL;DR: In the crystal structure of the title compound [CdBr2(C4H5N3O)2], two N atoms at the 3-position of the cytosine ligands and two bromide ions complete the distorted tetrahedral geometry around the CdII atom as mentioned in this paper.
Abstract: In the crystal structure of the title compound, [CdBr2(C4H5N3O)2], two N atoms at the 3-position of the cytosine ligands and the two bromide ions complete the distorted tetrahedral geometry around the CdII atom. The cytosine ligands of one type are paired through N—H⋯O hydrogen bonds while the cytosine ligands of another type are chained through N—H⋯O hydrogen bonds.
TL;DR: In this paper, the anti-CdCl2 structure of Ca2N has been investigated in the context of diffraction studies, and it has been shown that the c-axis dimension changes with the synthetic method employed.
Abstract: Ca2N adopts the anti-CdCl2 structure in which two sheets of calcium ions enclose a sheet of N3− ions, with each calcium bonded to three N3− at 2.4500 (3) A and each nitrogen octahedrally coordinated by six calciums. Within one calcium sheet, each metal has three others at 3.2944 (8) A and a further six at 3.6271 (3) A. The distance between two calcium layers with no intervening nitrogen layer is 4.3221 (6) A, and this intervening region contains no observable electron density. Neutron and X-ray powder diffraction studies have shown that the c-axis dimension changes with the synthetic method employed. In the single-crystal, c is significantly lower, reflecting the higher temperature employed in its formation.
TL;DR: In this article, a monoclinic crystal lattice with special channels parallel to the twofold screw axes along the b direction is described, which are occupied by disordered water mol-ecules.
Abstract: 2′,4′-Difluoro-4-hydroxybiphenyl-3-carboxylic acid (diflunisal) hydrate, C13H8F2O3·H2O, forms a monoclinic crystal lattice with special channels parallel to the twofold screw axes along the b direction. These channels are occupied by disordered water molecules. The crystal lattice consists of dimers of diflunisal, in which two molecules are linked together by a pair of hydrogen bonds between their respective carboxyl groups.
TL;DR: The title compound, C4H5FN3O+·C7H5O3−, exists as a hydrogen-bonded heterodimer of 5-fluorocytosinium and salicylate ions which are connected through a pair of nearly parallel specific N-H⋯O hydrogen bonds as discussed by the authors.
Abstract: The title compound, C4H5FN3O+·C7H5O3−, exists as a hydrogen-bonded heterodimer of 5-fluorocytosinium and salicylate ions which are connected through a pair of nearly parallel specific N—H⋯O hydrogen bonds. The heterodimer self-assembles via intermolecular N—H⋯O hydrogen bonds to form linear, as well as helical, hydrogen-bonded supramolecular chains that are interwoven into a three-dimensional network structure.
TL;DR: The hydrogen sulfate ions of the title compound, C16H36N+·HSO4−, form hydrogen-bonded dimers as discussed by the authors, and the hydrogen-sulfate ion of the compound can be represented as
Abstract: The hydrogensulfate ions of the title compound, C16H36N+·HSO4−, form hydrogen-bonded dimers.