- FLUORIDE-CONDUCTING SOLID ELECTROLYTES IN GALVANIC CELLS.
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Concentrated fluoride-excess solid solutions based on the alkaline earth fluorides and with CeF//3 and UF//4 as dopants are suitable solid electrolytes for application in thin film galvanic cells. Galvanic cells were fabricated using Pb or Ca as the anode
- Schoonman,Wapenaar,Oversluizen,Dirksen
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- Investigation of the α-BiO y F3 - 2y -based tysonite-type solid solutions by X-ray diffraction and impedance spectroscopy
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Tysonite solid solutions Bi1 - x M x (O, F) 3 - d (M = Na, Sr, or Nd) based on α-BiO y F 3 - 2y were prepared by solid-state synthesis at 873 K with subsequent quenching to ice-cold water. Aliovalent substitutions in both the cation and anion sublattices (M n+ → Bi3+ and O 2- → F-) made it possible to vary the anion-vacancy density. The solid solutions were characterized by X-ray diffraction and impedance spectroscopy. The homogeneity regions for the tysonite solid solution were determined; triangulation schemes at 873 K were suggested for the systems BiF3-BiOF-NaBiF4 and BiF3-BiOF-SrF2, and a scheme of the subsolidus phase diagram for the system BiO 0.1F2.8-NdF3 was suggested. In the system BiO0.1F2.8-NdF3, the transition temperature from the low-symmetry tysonite phase (phase II, space group P c1, Z = 6) to the high-symmetry one (phase I, space group P63/mmc, Z = 2) decreases with increasing anion-vacancy density. Conductivity measurements were performed in the temperature range 300-523 K and the frequency range from 5 to 1 × 106 Hz. The conductivity of samples in the system BiO 0.1F2.8-NdF3 increases with increasing bismuth-ion and anion-vacancy concentrations.
- Prituzhalov,Zakirov,Ardashnikova,Dolgikh
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- Soft-chemistry synthesis and characterization of bismuth oxyfluorides and ammonium bismuth fluorides
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Two bismuth oxyfluorides, BiOF and BiO0.5F2, have been prepared by soft chemistry. These two compounds are of interest for application as new type of positive electrode active materials in secondary lithium battery. BiOF was obtained directly from the fluorination of Bi 2O3 by a saturated aqueous solution of NH4F. BiO0.5F2 was obtained by the hydrolysis of β-NH 4BiF4 at 70°C. The ammonium bismuth fluoride β-NH4BiF4, which is a new orthorhombic form of NH4BiF4, was obtained by reacting BiF3 in a saturated aqueous solution of NH4F. Two other ammonium bismuth fluorides, (NH4)0.5BiF3.5 and NH 4Bi3F10, were also prepared by annealing β-NH4BiF4 at a relatively low temperature under inert atmosphere. The existence of the fluorite (NH4) 0.5BiF3.5 is reported for the first time in this paper.
- Bervas,Yakshinskiy,Klein,Amatucci
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- Suppression of modulations in fluorinated Bi-2201 phases
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Bi2Sr1.6La0.4CuO6.33 and Bi2Sr1.2La0.8CuO6.46 are fluorinated using XeF2 as a fluorinating agent and studied by X-ray powder diffraction and high-resolution electron microscopy. The highly fluorinated Bi-2201 phase undergoes a structural transformation that is accompanied by the formation of an I-centered tetragonal unit cell, the suppression of the √2ap x √2ap superstructure, the disappearance of the (BiO)2 modulation, and an elongation of the c parameter of about 1.65-1.77 A. The modification of the Bi2O2 block into a Bi2O2-δF2+δ block with filled tetrahedral interstitial positions is responsible for the observed structural changes and eliminates the mismatch between the (BiO) rock salt layers and the perovskite (CuO2) layers. The structure of the fluorinated material is compared with the structures of other intercalated Bi-based cuprates and phases composing Bi2(O,F)4 blocks in the structure.
- Hadermann,Khasanova,Van Tendeloo,Abakumov,Rozova,Alekseeva,Antipov
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- The structural investigation of Ba4Bi3F17
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The anion-excess ordered fluorite-related phase Ba4Bi 3F17 has been synthesized by a solid state reaction of BaF2 and BiF3 at 873K. The crystal structure of Ba 4Bi3F17 has been studied using electron diffraction and X-ray powder diffraction (a=11.2300(2)A, c=20.7766(5)A, S.G. R3, RI=0.020, RP=0.036). Interstitial fluorine atoms in the Ba4Bi3F17 structure are considered to form isolated cuboctahedral 8:12:1 clusters. The structural relationship between Ba4Bi3F17 and similar rare-earth-based phases is discussed.
- Dombrovski,Serov,Abakumov,Ardashnikova,Dolgikh,Van Tendeloo
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- Fluorite-like phases in the BaF2-BiF3-Bi 2O3 system - Synthesis, conductivity and defect clustering
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A fluorite-like solid solution Ba1 - xBixO zF2 + x - 2z on the basis of cubic BaF2 was synthesised in the BaF2-Bi2O3-BiF3 system and the homogeneity range at 873 K was determined. The samples were studied by X-ray powder diffraction and electron diffraction, and their transport properties were measured by the complex impedance method at 300-623 K. Tendencies of variation of lattice parameters and transport properties were determined. These tendencies are discussed on the basis of a defect clustering hypothesis. Thermal treatment at 573 K of the solid solution, quenched from 873 K results in the formation of a new ordered tetragonal fluorite-like phase with lattice parameters a = 9.5355(4) ?, c = 18.151(1) ?.
- Serov,Dombrovski,Ardashnikova,Dolgikh,El Omari, Malika,El Omari, Mohamed,Abaouz,Senegas,Chaban,Abakumov,Van Tendeloo
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- Unusual neutral ligand coordination to arsenic and antimony trifluoride
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The preparations and spectroscopic characterisation of the hydrolytically unstable As(iii) complexes, [AsF3(OPR3)2] (R = Me or Ph) and [AsF3{Me2P(O)CH2P(O)Me 2}] are described and represent the first examples of complexes of AsF3 with neutral ligands. The crystal structure of [AsF 3{Me2P(O)CH2P(O)Me2}] contains dimers with bridging diphosphine dioxide, but there are also long contacts between the dimers to neighbouring phosphine oxide groups, completing a very distorted six-coordination at arsenic and producing a weakly associated polymer structure. The reaction of AsF3 with OAsPh3 affords Ph3AsF2, and no arsine oxide complex was formed. Reaction of SbF3 with OER3 (R = Me or Ph, E = P or As), Me 2P(O)CH2P(O)Me2 and Ph2P(O)(CH 2)nP(O)Ph2 (n = 1 or 2) in MeOH produces [SbF3(OER3)2], [SbF3{Me 2P(O)CH2P(O)Me2}] and [SbF3{Ph 2P(O)(CH2)nP(O)Ph2}] respectively. The X-ray structures reveal that the complexes contain square pyramidal SbF 3O2 cores with apical F and cis disposed pnictogen oxides. However, whilst [SbF3(OER3)2] (R = Ph: E = P or As; R = Me: E = As) and [SbF3{Ph2P(O)CH 2P(O)Ph2}] are monomeric, [SbF3{Me 2P(O)CH2P(O)Me2}] is a dimer with bridging diphosphine dioxides producing a twelve-membered ring, and [SbF 3{Ph2P(O)(CH2)2P(O)Ph2}] is a chain polymer with diphosphine dioxide bridges. In the OAsR3 reactions with SbF3, R3AsF2 are also formed. Notably the Sb-O(P) bonds are shorter than As-O(P), despite the covalent radii (As 3. IR and multinuclear (1H, 19F and 31P) NMR data are reported and discussed. BiF3 does not react with pnictogen oxide ligands under similar conditions and halide exchange of bismuth chloro complexes with Me3SnF gave BiF3.
- Levason, William,Light, Mark E.,Maheshwari, Seema,Reid, Gillian,Zhang, Wenjian
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p. 5291 - 5297
(2011/06/27)
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- Synthesis and structure of an air-stable hypervalent organobismuth (III) perfluorooctanesulfonate and its use as high-efficiency catalyst for Mannich-type reactions in water
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An air-stable hypervalent organobismuth (III) perfluorooctanesulfonate was synthesized and characterized by spectroscopic and X-ray crystallographic techniques, and found to exhibit high catalytic efficiency towards one-pot Mannich-type reaction of ketones with aromatic aldehydes and aromatic amines in water. This catalyst also shows good recyclability and reusability. This catalytic system would provide a simple, efficient and 'green' avenue towards the synthesis of β-amino ketones.
- Zhang, Xiaowen,Yin, Shuangfeng,Qiu, Renhua,Xia, Jun,Dai, Weili,Yu, Zhenying,Au, Chak-Tong,Wong, Wai-Yeung
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p. 3559 - 3564
(2010/01/18)
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- Study of a fluorite-like solid solution Na0.5 - xBi 0.5 + xO2x - δF2 + 2δ - 2x by X-ray powder diffraction and 19F NMR
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The homogeneity range of a fluorite-like solid solution in the NaF-Bi 2O3-BiF3 system has been studied by the isothermal annealing method at 600°C, X-ray powder diffraction, and 19F NMR. The diagram of the dependence of the cubic unit cell parameter on the solid solution composition has been constructed. The diagram shows a mountain ridge. NMR shows that the experimental dependence of the number of introduced fluorine atoms along the line with a constant nonstoichiometry (δ = 0.4) in Na0.5 - xBi0.5 + x(O,F)2.40 is nonmonotone. The anion-excessive fluorite-like solid solution Na 0.5 - xBi0.5 + xO2x - δF 2 + 2δ - 2x structural heterogeneities that influence changes in unit cell parameters and the number of introduced fluorine atoms with a change in the composition of a sample. These structural heterogeneities are manifested in the presence of two concentration regions of the homogeneity range and are presumably described by the existence of two major types of clusters - cuboctahedral and triangular - in the solid solution.
- Dombrovski,Serov,Ardashnikova,Dolgikh
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p. 734 - 740
(2008/10/08)
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- Kinetics and mechanism of oxidation of nitrites with Bi(V) in HClO4-HF mixture
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Kinetics of oxidation of nitrite ion (NO2-) with Bi(V) fluoride complex have been investigated in HClO4-HF mixture. The reaction is first order in each reactant. Hydrogen ion (H+) and ionic strength have inverse effect on the reaction rate. The effect of HF and added fluoride ion (F-) are found to be negligible. The mode of electron transference from the substrate (NO2-) to the oxidant Bi(V) has been indicated via a bridged outer-sphere mechanism.
- Roy, Ramesh Kumar,Mishra, Prem Mohan,Ashok Kumar, Jha,Jha
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p. 187 - 189
(2007/10/03)
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- Properties and reactions of tris(2,6-difluorophenyl)bismuth(III) and tris(2,6-difluorophenyl)bismuth(V) derivatives
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(2,6-F2C6H3)3BiF2 and (2,6-F2C6H3)3BiCl2 are prepared oxidizing (2,6-F2C6H3)3Bi with XeF2
- Lewe,Naumann,Nowicki,Schneider,Tyrra
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p. 122 - 128
(2008/10/09)
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- Pentafluorophenyliodine(V) Compounds. 2. Pentafluorophenyliodine Tetrafluoride C6F5IF4: Synthesis via Fluorine-Aryl-Subsitution on IF5 - Properties and Structure
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The nucleophilic fluorine-aryl substitution reaction on IF5 with pentafluorophenyl, Bi(C6F5)3, leads to C6F5IF4 in good yields and high purity. The thermal stability of C6F5IF4 and its NMR spectrometric behaviour in solution will be discussed in comparison to IF5. In addition data of themolecular and crystal structure of the monovalent iodine parent compoun d C5F5I will be given.
- Frohn, H. J.,Goerg, S.,Henkel, G.,Laege, M.
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