- Electron Ionization Mass Spectrum of Tellurium Hexafluoride
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The electron ionization mass spectrum of tellurium hexafluoride (TeF6) is reported for the first time. The starting material was produced by direct fluorination of Te metal or TeO2 with nitrogen trifluoride. Formation of TeF6 was confirmed through cryogenic capture of the tellurium fluorination product and analysis through Raman spectroscopy. The eight natural abundance isotopes were observed for each of the set of fragment ions: TeF5+, TeF4+ TeF3+, TeF2+, TeF1+, and Te+, Te2+. A trend in increasing abundance was observed for the odd fluoride bearing ions, TeF1+ 3+ 5+, and a decreasing abundance was observed for the even fragment series, Te(F0)+ > TeF2+ > TeF4+ > TeF6+, with the molecular ion TeF6+ not observed at all. Density functional theory based electronic structure calculations were used to calculate optimized ground state geometries of these gas phase species, and their relative stabilities explain the trends in the data and the lack of observed signal for TeF6+. (Chemical Equation Presented).
- Clark, Richard A.,McNamara, Bruce K.,Barinaga, Charles J.,Peterson, James M.,Govind, Niranjan,Andersen, Amity,Abrecht, David G.,Schwantes, Jon M.,Ballou, Nathan E.
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- Plasmachemical synthesis of the binary hexafluorides of Mo, Os, Ir, Te, and U
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Starting from the respective metal, we have synthesized the binary hexafluorides MF6 of M = Mo, Os, Ir, Te, and U by the use of a remote fluorine plasma source using a mixture of Ar and NF3 as the feed gas. The formation of the binary hexafluorides was confirmed by several different spectroscopic methods including IR, Raman, UV/VIS, and NMR spectroscopy.
- Buchner, M. R.,Chemnitz, T.,Kraus, F.,Petry, W.
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- Separation of metallic residues from the dissolution of a high-burnup BWR fuel using nitrogen trifluoride
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Nitrogen trifluoride (NF3) was used to fluorinate the metallic residue from the dissolution of a high burnup, boiling water reactor fuel (～70 MWd/kgU). The washed residue included the noble-metal phase (containing ruthenium, rhodium, palladium, technetium, and molybdenum), smaller amounts of zirconium, selenium, tellurium, and silver, along with trace quantities of plutonium, uranium, cesium, cobalt, europium, and americium, likely as their oxides. Exposing the noble metal phase to 10% NF3 in argon, between 400 and 550 °C, removed molybdenum and technetium near 400 °C as their volatile fluorides, and ruthenium near 500 °C as its volatile fluoride. The events were thermally and temporally distinct and the conditions specified provide a recipe to separate these transition metals from each other and from the nonvolatile residue. Depletion of the volatile fluorides resulted in substantial exothermicity. Thermal excursion behavior was recorded with the thermal gravimetric instrument operated in a non-adiabatic, isothermal mode; conditions that typically minimize heat release. Physical characterization of the noble-metal phase and its thermal behavior are consistent with high kinetic velocity reactions encouraged by the nanoparticulate phase or perhaps catalytic influences of the mixed platinum metals with nearly pure phase structure. Post-fluorination, only two products were present in the residual nonvolatile fraction. These were identified as a nano-crystalline, metallic palladium cubic phase and a hexagonal rhodium trifluoride (RhF3) phase. The two phases were distinct as the sub-μm crystallites of metallic palladium were in contrast to the RhF3 phase, which grew from the parent, nano-crystalline noble-metal phase during fluorination, to acicular crystals exceeding 20-μm in length.
- McNamara, Bruce K.,Buck, Edgar C.,Soderquist, Chuck Z.,Smith, Frances N.,Mausolf, Edward J.,Scheele, Randall D.
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supporting information
p. 1 - 8
(2014/05/06)
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- Industrial fluorine compounds
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Technological research in the area of the industrial fluorine-containing compounds: ozone safe fluorocarbons (freons), fluoro-olefins, compounds with the functional groups, thermoresistant liquids, oils, lubricants, fluorine surfactants and other.
- Barabanov,Maksimov
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p. 1133 - 1141
(2009/12/01)
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- Heptacoordination: Pentagonal bipyramidal XeF7+ and TeF7- ions
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The TeF7- anion was studied experimentally by vibrational and 19F and 125Te NMR spectroscopy. Ab initio calculations employing effective core potentials and density functional theory calculations at the self-consistent nonlocal level with the nonlocal exchange potential of Becke and the nonlocal correlation functional of Perdew were used for the analysis of the isoelectronic series TeF7-, IF7, XeF7+. It is shown that XeF7+ is a stable structure, that all three members of this series possess a pentagonal bipyramidal equilibrium geometry, and that from the two closest lying saddle point geometries only the monocapped trigonal prism, but not the monocapped octahedron, is a transition state for the intramolecular axial-equatorial ligand exchange. The results from a normal coordinate analysis reveal the existence of an unusual new effect which counteracts the ligand-ligand repulsion effect and is characterized by axial bond stretching encouraging equatorial bond stretching. While in TeF7- the ligand-ligand repulsion effect dominates, in XeF7+ the new effect becomes preponderant.
- Christe, Karl O.,Dixon, David A.,Sanders, Jeremy C. P.,Schrobilgen, Gary J.,Wilson, William W.
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p. 9461 - 9467
(2007/10/02)
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- Thermodynamic properties of tungsten ditelluride (WTe2). II. Standard molar enthalpy of formation at the temperature 298.15 K
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The standard molar enthalpies of formation of WTe2(cr) and TeF6(g) have been determined by combustion calorimetry in high-pressure fluorine: ΔfHmo(WTe2, cr, 298.15K) = -(38+/-5)kJmol-1, and ΔfHsub
- O'Hare, P. A. G.,Hope, G. A.
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p. 639 - 647
(2007/10/02)
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- FxXe(OTeF5)3-x+, O=XeFx(OTeF5)3-x+ (x = 0-2), and O2XeOTeF5+ cations: Their preparation and characterization in solution by 129Xe and 19F NMR spectroscopy
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Solvolysis reactions of the parent compounds, Xe(OTeF5)4 and O=Xe(OTeF5)4, in the strong F/OTeF5 acceptor solvent SbF5, led to OTeF5/F ligand redistribution and formation of two series of novel mixed-xenon cations, FxXe(OTeF5)3-x+, O=XeFx(OTeF5)3-x+ (x = 0-2), and O2XeOTeF5+. The previously known XeF3+, XeOF3+, and XeO2F+ cations were observed in addition to the mixed cations. Decomposition of O=XeF2OTeF5+ and O=XeF-(OTeF5)2+ in SbF5 solution led respectively to formation of the previously known XeO2F+ cation and its novel OTeF5 analog O2XeOTeF5+. The O=Xe(OTeF5)3+ cation was not observed in the O=Xe(OTeF5)4/SbF5 systems but was prepared by allowing O=Xe(OTeF5)4 and "Sb(OTeF5)5" to react in SO2ClF. All three series of cations have been characterized in solution by 129Xe and 19F NMR spectroscopy.
- Syvret, Robert G.,Mitchell, Kenneth M.,Sanders, Jeremy C. P.,Schrobilgen, Gary J.
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p. 3381 - 3385
(2008/10/08)
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- Standard molar enthalpy of formation at 298.15 K of the β-modification of molybdenum ditelluride
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Fluorine-combustion calorimetry of a high-purity sample of molybdenum ditelluride has yielded the standard molar enthalpy of formation: ΔfH0m(MoTe2, cr, β, 298.15 K) = -(84.2 +/- 4.6) kJ * mol-1.At 298.15 K, the enthalpy of the hypothetical β-to-α transition in MoTe2 is approximately -6 kJ * mol-1.The present result for ΔfH0m(MoTe2) has been combined with literature values for the decomposition pressures of MoTe2 to yield ΔfH0m(Mo3Te4, cr, 298.15 K) = -(185 +/- 10) kJ * mol-1.Our previously published ΔfH0m(TeF6) (Trans.Faraday Soc. 1966, 62, 558) has been revised slightly to -(1371.8 +/- 1.8) kJ * mol-1.
- O'Hare, P. A. G.,Hope, G. A.
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p. 701 - 708
(2007/10/02)
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- Some investigations of the chemistry of tellurium chloride pentafluoride, its reaction with caesium fluoride, and the preparation of cis and trans methoxytellurium(VI)chloride tetrafluoride, (CH3O)TeClF4
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The reaction of TeClF5 with CH3OH, and CH3OSiMe3, leads to a mixture of cis- and trans-(CH3O)TeClF4 in a ratio of 1:6, as well as some unidentified Te(IV) product.The vibrational spectrum of the 1:6 mixture of cis- and trans-(CH3O)TeClF4 was accounted for on the basis of the predominant pseudo-C4v trans isomer.TeClF5 is unreactive towards anhydrous HF, SbF5, AlCl3, SO2, F2, and ClF at room temperature.Over the temperature range 70-250 deg C it thermally decomposes to TeF6, TeF4, and Cl2.It slowly reacts with CsF to form CsTeF5, TeF6, Cl2, and small amounts of ClF, and with HNMe2 it is also reduced to form TeF4*HNMe2.
- Lawlor, Lawrence J.,Passmore, Jack
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p. 1477 - 1482
(2007/10/02)
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- Synthesis and characterization of TeF5OF
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A new method for the synthesis of hypofluorites was discovered utilizing fluorine fluorosulfate as the fluorinating agent. The method was successfully applied to the high-yield synthesis of the new hypofluorite TeF5OF. The compound was also prepared in lower yield by the fluorination of TeF5OH with a concentrated NF4HF2 solution. The physical properties and infrared, Raman, 19F NMR and mass spectra of TeF5OF are reported. The vibrational spectra of TeF5OCl were redetermined, and complete vibrational assignments are given for TeF5OF and TeF5OCl.
- Schack, Carl J.,Wilson, William W.,Christe, Karl O.
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- Preparation and Properties of TiCl4-n(OTeF5)n (n = 1 - 4), Cs2, and Ti(OTeF5)4 * 2 POCl3
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TiCl4 reacts with HOTeF5 to afford TiCl3OTeF5.This compound dismutates via TiCl2(OTeF5)2 and TiCl(OTeF5)3 to Ti(OTeF5)4.With CsOTeF5 the latter forms Cs2 but not Cs.Ti(OTeF5)4 shows strong Lewis acid behavior.Interaction with POCl3, (CH3)2SO, CH3CN, CH3O2OCH3, and CH3NO2 was studied and a correlation of 19F NMR data of the F5TeO group with the donor numbers of the mentioned bases was undertaken.
- Schroeder, Klaus,Sladky, Fritz
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p. 1414 - 1419
(2007/10/02)
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