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Acta Crystallographica. Section C, Structural Chemistry

Belakavadi K Sagar, Kachigere B Harsha, Hemmige S Yathirajan, Kanchugarakoppal S Rangappa, Ravindranath S Rathore, Christopher Glidewell
In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C21H19F4N3O2S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C21H19ClF3N3O2S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C22H22F3N3O2S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Farahnaz Hamzehee, Mehrdad Pourayoubi, Marek Nečas, Duane Choquesillo-Lazarte
The N-H...O hydrogen bond is the characteristic interaction in the crystal structures of N-benzyl-P-phenyl-N'-(p-tolyl)phosphonic diamide, C20H21N2OP or (C6H5)P(O)(NHCH2C6H5)(NHC6H4-p-CH3), (I), diphenylphosphinic 1-methylpropylamide, C16H20NOP or (C6H5)2P(O)[NHCH(CH3)(C2H5)], (II), (S)-1-phenylethylammonium N-[(S)-1-phenylethyl]phenylphosphonamidate, C8H12N(+)·C14H15NO2P(-) or [S-(C6H5)CH(CH3)NH3][(C6H5)P(O){S-NHCH(CH3)(C6H5)}(O)], (III), and (4-methylbenzyl)ammonium diphenylphosphinate, C8H12N(+)·C12H10O2P(-) or [4-CH3-C6H4CH2NH3][(C6H5)2P(O)(O)], (IV)...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Alberto Báez-Castro, Jesús Baldenebro-López, Laura Ceballos-Mendivil, Perla P Román-Bravo, Herbert Höpfl, Valentín Miranda-Soto, Daniel Glossman-Mitnik, Adriana Cruz-Enríquez, José J Campos-Gaxiola
The possibility of using less expensive and nontoxic metals, such as copper, as substitutes for more expensive heavy metals in the synthesis of new transition-metal complexes to be used as sensitizers in dye-sensitized solar cells (DSSCs) has stimulated research in this field. The novel photoluminescent copper(I) complex bis(triphenylphosphane-κP)[trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline-κ(2)N(2),N(3)]copper(I) hexafluorophosphate, [Cu(I)(C18H15N5)(C18H15P)2]PF6, has been successfully synthesized and characterized by IR and (1)H NMR spectroscopy, as well as by single-crystal X-ray diffraction and thermogravimetric analysis...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Laura M Wickham, Joseph M Tanski, Jocelyn M Nadeau
Molecules with well-defined structures that feature closely stacked aromatic rings are important for understanding π-π interactions. A previously reported C-shaped molecule with bithiophene-substituted quinoxaline rings suspended from an aliphatic bridge that holds the aromatic rings in close proximity exists as a pair of syn and anti diastereomers. The anti isomer, namely (1α,2β,4β,5α,16α,17β,19β,20α)-1,5,16,20-tetrachloro-31,31,32,32-tetramethoxy-11,26-bis[5-(thiophen-2-yl)thiophen-2-yl]-7,14,22,29-tetraazanonacyclo[18...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Clifton R Hamilton, Michael J Zdilla
Polynuclear metal clusters frequently feature geometric structural features not common in traditional coordination chemistry. These structures are of particular interest to bioinorganic chemists studying metallocluster enzymes, which frequently possess remarkably unusual inorganic structures. The structure of the manganese cluster μ5-oxido-di-μ3-phenoxido-hexa-μ-phenoxido-hexakis(pyridine-κN)hexamanganese(II) pyridine monosolvate, [Mn5(C6H5O)8O(C5H5N)6]·C5H5N or Mn(II)5(μ-OPh)6(μ3-OPh)2(μ5-O)(Py)6·Py, containing an unusual trigonal bipyramidal central oxide, is described...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
AbdelAziz Jalil, Rebecca N Clymer, Clifton R Hamilton, Shivaiah Vaddypally, Michael R Gau, Michael J Zdilla
Due to the flammability of liquid electrolytes used in lithium ion batteries, solid lithium ion conductors are of interest to reduce danger and increase safety. The two dominating general classes of electrolytes under exploration as alternatives are ceramic and polymer electrolytes. Our group has been exploring the preparation of molecular solvates of lithium salts as alternatives. Dissolution of LiCl or LiPF6 in pyridine (py) or vinylpyridine (VnPy) and slow vapor diffusion with diethyl ether gives solvates of the lithium salts coordinated by pyridine ligands...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Marimuthu Mohana, Packianathan Thomas Muthiah, Colin D McMillen
The design of a pharmaceutical cocrystal is based on the identification of specific hydrogen-bond donor and acceptor groups in active pharmaceutical ingredients (APIs) in order to choose a `complementary interacting' molecule that can act as an efficient coformer. 5-Fluorouracil (5FU) is a pyrimidine derivative with two N-H donors and C=O acceptors and shows a diversity of hydrogen-bonding motifs. Two 1:1 cocrystals of 5-fluorouracil (5FU), namely 5-fluorouracil-4-methylbenzoic acid (5FU-MBA), C4H3FN2O2·C8H8O2, (I), and 5-fluorouracil-3-nitrobenzoic acid (5FU-NBA), C4H3FN2O2·C7H5NO4, (II), have been prepared and characterized by single-crystal X-ray diffraction...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Ying Chun He, Ji Gang Pan, Dian Sheng Liu
Calix[4]pyrroles act as powerful receptors for electron-rich neutral guests and anionic guests in organic solvents. For the electron-rich neutral guest pyridine N-oxide, calix[4]pyrrole, with a deep cavity, provides an appropriate environment. The ability of calix[4]pyrrole to host binding guest molecules is the result of hydrogen bonding, π-π, C-H...π and hydrophobic interactions of the cavity. The novel title complex, C52H40D12N4O4·C5H5NO·C2H3N, based on d12-meso-tetrakis(4-methoxyphenyl)-meso-tetramethylcalix[4]pyrrole, has been assembled using an excess of pyridine N-oxide and is the first deuterated complex of calix[4]pyrrole...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Xue Ru Wang, Jian Ping Ma, Yu Bin Dong
Organic ligands and counter-anions influence the coordination spheres of metal cations and hence the construction of coordination polymers (CPs). The specific bent geometries of five-membered heterocyclic triazole bridging organic ligands are capable of generating CPs with novel patterns not easily obtained using rigid linear ligands. A multidentate 4-aminotriazole-bridged organic ligand, namely 4-amino-3,5-bis(4,3'-bipyridyl-5'-yl)-4H-1,2,4-triazole (L) has been prepared and used to synthesize two Co(II) coordination polymers, namely poly[[[μ2-4-amino-3,5-bis(4,3'-bipyridyl-5'-yl)-4H-1,2,4-triazole-κ(2)N:N']bis(methanol-κO)cobalt(II)] bis(perchlorate)], {[Co(C22H16N8)2(CH3OH)2](ClO4)2}n, (I), and poly[[μ3-4-amino-3,5-bis(4,3'-bipyridyl-5'-yl)-4H-1,2,4-triazole-κ(3)N:N':N'']dichloridocobalt(II)], [CoCl2(C22H16N8)]n, (II), using CoX2 salts [X = ClO4 for (I) and Cl for (II)] under solvothermal conditions...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Cameron Black, Philip Lightfoot
Vanadium fluorides with novel crystal-chemical features and interesting physical properties can be prepared by solvothermal synthetic routes. The title compound, guanidinium hexafluoridovanadate(III), has a cubic structure (space group Pa-3), exhibiting isolated regular VF6 octahedral units, which are hydrogen bonded to protonated guanidinium moieties. Although the VF6 octahedral units are not linked directly together, there are structural similarities between this crystal structure and those of the wider family of perovskite materials, in particular, hybrid perovskites based on extended ligands such as cyanide...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Nicolas J Vigilante, Manish A Mehta
We report an analysis of the (13)C solid-state NMR chemical shift data in a series of four cocrystals involving two active pharmaceutical ingredient (API) mimics (caffeine and theophylline) and two diacid coformers (malonic acid and glutaric acid). Within this controlled set, we make comparisons of the isotropic chemical shifts and the principal values of the chemical shift tensor. The dispersion at 14.1 T (600 MHz (1)H) shows crystallographic splittings in some of the resonances in the magic angle spinning spectra...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Gregor Mali
Ab initio prediction of sensible crystal structures can be regarded as a crucial task in the quickly-developing methodology of NMR crystallography. In this contribution, an evolutionary algorithm was used for the prediction of magnesium (poly)sulfide crystal structures with various compositions. The employed approach successfully identified all three experimentally detected forms of MgS, i.e. the stable rocksalt form and the metastable wurtzite and zincblende forms. Among magnesium polysulfides with a higher content of sulfur, the most probable structure with the lowest formation energy was found to be MgS2, exhibiting a modified rocksalt structure, in which S(2-) anions were replaced by S2(2-) dianions...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Tetsuo Oikawa, Manabu Okumura, Tsunehisa Kimura, Yusuke Nishiyama
A combination of solid-state NMR (ssNMR) and electron diffraction (ED) has been used to determine the crystalline polymorphs in small-organic microcrystalline molecules. Although (13)C cross-polarization magic angle spinning (CPMAS) is a widely used method for determining crystalline polymorphs, even in a mixture, it sometimes fails if the molecular conformations are similar. On the other hand, ED can, in principle, differentiate crystalline forms with different lattice parameters, even when they have very similar molecular conformations...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Christel Gervais, Cameron Jones, Christian Bonhomme, Danielle Laurencin
With the increasing number of organocalcium and organomagnesium complexes under development, there is a real need to be able to characterize in detail their local environment in order to fully rationalize their reactivity. For crystalline structures, in cases when diffraction techniques are insufficient, additional local spectroscopies like (25)Mg and (43)Ca solid-state NMR may provide valuable information to help fully establish the local environment of the metal ions. In this current work, a prospective DFT investigation on crystalline magnesium and calcium complexes involving low-coordination numbers and N-bearing organic ligands was carried out, in which the (25)Mg and (43)Ca NMR parameters [isotropic chemical shift, chemical shift anisotropy (CSA) and quadrupolar parameters] were calculated for each structure...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Eddy Dib, Mélanie Freire, Valérie Pralong, Tzonka Mineva, Bruno Alonso
The structure of the silica AST zeolites (octadecasil) synthesized in fluoride medium using tetramethylammonium (TMA) as the organic structure-directing agent has been reinvestigated using (14)N NMR quadrupolar parameters and DFT calculations. The value of the experimental (14)N quadrupolar coupling constant (CQ = 27 kHz) is larger than expected for a TMA cation possessing a high degree of motion. The analysis of a DFT-optimized octadecasil cluster along with the comparison between measured and calculated (14)N NMR parameters demonstrate the presence of weak C-H...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Daniel M Dawson, Richard I Walton, Stephen Wimperis, Sharon E Ashbrook
The aluminophosphate (AlPO) JDF-2 is prepared hydrothermally with methylammonium hydroxide (MAH(+)·HO(-), MAH(+) = CH3NH3(+)), giving rise to a microporous AEN-type framework with occluded MAH(+) cations and extra-framework (Al-bound) HO(-) anions. Despite the presence of these species within its pores, JDF-2 can hydrate upon exposure to atmospheric moisture to give AlPO-53(A), an isostructural material whose crystal structure contains one molecule of H2O per formula unit. This hydration can be reversed by mild heating (such as the frictional heating from magic angle spinning)...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Darren Henry Brouwer, Sylvian Cadars, Kathryn Hotke, Jared Van Huizen, Nicholas Van Huizen
Structure determination of layered materials can present challenges for conventional diffraction methods due to the fact that such materials often lack full three-dimensional periodicity since adjacent layers may not stack in an orderly and regular fashion. In such cases, NMR crystallography strategies involving a combination of solid-state NMR spectroscopy, powder X-ray diffraction, and computational chemistry methods can often reveal structural details that cannot be acquired from diffraction alone. We present here the structure determination of a surfactant-templated layered silicate material that lacks full three-dimensional crystallinity using such an NMR crystallography approach...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Raynald Giovine, Christophe Volkringer, Julien Trébosc, Jean Paul Amoureux, Thierry Loiseau, Olivier Lafon, Frédérique Pourpoint
The metal-organic framework MIL-53(Al) (aluminium terephthalate) exhibits a structural transition between two porous structures with large pore (lp) or narrow pore (np) configurations. This transition, called the breathing effect, is observed upon changes in temperature or external pressure, as well as with the adsorption of guest molecules, such as H2O, within the pores. We show here how these different pore openings can be detected by observing the dephasing of (13)C magnetization under (13)C-(27)Al dipolar couplings using Rotational-Echo Saturation-Pulse Double-Resonance (RESPDOR) solid-state NMR experiments with Simultaneous Frequency and Amplitude Modulation (SFAM) recoupling...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Hannah E Kerr, Lorna K Softley, Kuthuru Suresh, Paul Hodgkinson, Ivana Radosavljevic Evans
Naproxen (NPX) is a nonsteroidal anti-inflammatory drug with pain- and fever-relieving properties, currently marketed in the sodium salt form to overcome solubility problems; however, alternative solutions for improving its solubility across all pH values are desirable. NPX is suitable for cocrystal formation, with hydrogen-bonding possibilities via the COOH group. The crystal structure is presented of a 1:1 cocrystal of NPX with picolinamide as a coformer [systematic name: (S)-2-(6-methoxynaphthalen-2-yl)propanoic acid-pyridine-2-carboxamide (1/1), C14H14O3·C6H6N2O]...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
Patrick M J Szell, Shaina A Gabriel, Russell D D Gill, Shirley Y H Wan, Bulat Gabidullin, David L Bryce
Halogen bonding is a noncovalent interaction between the electrophilic region of a halogen (σ-hole) and an electron donor. We report a crystallographic and structural analysis of halogen-bonded compounds by applying a combined X-ray diffraction (XRD) and solid-state nuclear magnetic resonance (SSNMR) approach. Single-crystal XRD was first used to characterize the halogen-bonded cocrystals formed between two fluorinated halogen-bond donors (1,4-diiodotetrafluorobenzene and 1,3,5-trifluoro-2,4,6-triiodobenzene) and several nitrogen-containing heterocycles (acridine, 1,10-phenanthroline, 2,3,5,6-tetramethylpyrazine, and hexamethylenetetramine)...
March 1, 2017: Acta Crystallographica. Section C, Structural Chemistry
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