cas 7783-82-6, Tungsten hexafluoride | Articles data

Articles about 7783-82-6Total 13 be found

Kinetics of interaction of tungsten metal with a fluoropolymer
The kinetics of the interaction of tungsten metal with a copolymer of tetrafluoroethylene and vinylidene difluoride (TFE-VDF) has been studied by mass spectrometry (MS), thermogravimetry (TG), and differential scanning calorimetry (DSC). Measurements were
Tarasov,Arkhangel'skii,Alikhanyan
p. 161 - 165
(2009)
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Intercalation of WF6 in the interlayer space of multiwall carbon nanotubes - Structural and morphological aspects
The reactivity of multiwall carbon nanotubes toward WF6, a strong Lewis acid, has been studied. A material of nominal composition C 36WF6 has been obtained and characterized by X-ray diffraction. Intercalation between pseudo-graphitic layers has been evidenced, leading to a staging phenomenon at the nanometer scale. A structural model is proposed and the intercalation chemistry of multiwalled carbon nanotubes is discussed.
Claves,Giraudet,Schouler,Gadelle,Hamwi
p. 1 - 5
(2004)
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Development and implementation of industrial technologies for synthesis of fluorine compound with the application of elemental fluorine
A survey is given on the application of elemental fluorine in chemical plants and research centers of Russian Federation.
Pashkevich,Barabanov,Maksimov
p. 1142 - 1148
(2009/12/01)

Chemical interaction of fluoropolymers with transition metals
Chemical interaction of transition metals (Mo, W, Ta, Nb, and Ti) with a tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer (21 mol % TFE + 79 mol % VDF) has been studied by differential scanning calorimetry (DSC) and mass spectrometry. The DSC c
Tarasov,Alikhanian,Arkhangel'Skii
p. 809 - 813
(2009/12/01)

Reactions of Ruthenium Pentafluoride with Refractory Metals
Differential thermal analysis, X-ray powder diffraction, and IR spectroscopy were the tools used to study reactions of powdered and compact samples of V, Nb, Mo, and W, as well as of Si and Ge, with RuF5. The onset temperatures and products of the reactions were determined. The possibility of using exchange reactions to apply ruthenium coatings to the simple substances that form volatile higher fluorides was shown.
Rakov,Dzhalavyan,Nikitin
p. 1003 - 1005
(2008/10/08)

Thermodynamic properties of tungsten ditelluride (WTe2). II. Standard molar enthalpy of formation at the temperature 298.15 K
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.
p. 639 - 647
(2007/10/02)

Standard molar enthalpy of formation at 298.15 K of the β-modification of molybdenum ditelluride
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.
p. 701 - 708
(2007/10/02)

Mechanism for selectivity loss during tungsten CVD
We have investigated possible mechanisms for the loss of selectivity (i.e., deposition on silicon dioxide) during tungsten CVD by reduction of tungsten hexafluoride and found strong evidence that selectivity loss is initiated by desorption of tungsten sub
Creighton
p. 271 - 276
(2008/10/08)

Standard molar enthalpy of formation by fluorine-combustion calorimetry of tungsten diselenide (WSe2). Thermodynamics of the high-temperature vaporization of WSe2. Revised value of the standard molar enthalpy of formation of molybdenite (MoS2)
A high-purity sample of WSe2, containing in total mass fraction less than 1 x 10-4 of oxygen and other impurities, has been synthesized by combination of the elements.The standard specific energy of combustion of pure WSe2 in fluorine, as measured by high-precision calorimetry, is -(10993.7+/-15.0) J*g-1, and the derived standard molar enthalpy of formation ΔfHm0 is -(185.3+/-5.5) kJ*mol-1 at T = 298.15 K and p0 = 0.101325 MPa.This result is compared with other literature values, and the equilibrium partial pressures of Se2(g) and Se(g) are estimated for decomposition of WSe2 to and 1/2WSe2 to .Our published result (J.Chem.Thermodynamics 1970, 2, 797) for ΔfHm0(MoS2) at 298.15 K has been revised to -(271.8+/-4.9) kJ*mol-1.
O'Hare, P. A. G.,Lewis, Brett M.,Parkinson, B. A.
p. 681 - 692
(2007/10/02)

Perfluoroammonium and cesium fluorotungstates
The syntheses of NF4+ salts containing fluorotungstate anions were studied. The new NF4WOF5 salt was prepared by the reaction of WOF4 with a concentrated solution of NF4HF2 in anhydrous HF. It is a white solid, stable up to 60°C. At higher temperatures it decomposes to NF4W2O2F9, NF3, OF2, and WF6. The ionic nature of NF4WOF5 in the solid state was established by vibrational spectroscopy, but in dilute HF solutions the WOF5- anion solvolyzes according to 2WOF5- + HF ? W2O2F9- + HF2-. In HF solution WF6- is readily oxidized by NF4+ to yield WF6 and NF3. The syntheses and some reaction chemistry and properties of CsWOF5, CsW2O2F9, Cs2WO2F4, and CsWF6 are discussed.
Wilson, William W.,Christe, Karl O.
p. 4139 - 4143
(2008/10/08)

Preparation and study by raman spectroscopy of KrF2·MOF4, XeF2·MOF4, and XeF2·2MOF4 (M = Mo, W) and a solution 19F NMR study of KrF2·nMoOF4 (n = 1-3) and KrF2·WOF4
The first krypton difluoride-metal oxide fluoride adducts have been prepared by reaction of KrF2 with MOF4 (M = Mo, W) in SO2ClF solution at low temperatures. The 19F NMR spectra of KrF2·nMoOF4 (n = 1-3) and KrF2·WOF4 in solution show that they are best formulated as essentially covalent structures containing Kr?F?M bridges and mononuclear or polynuclear metal oxide fluoride moieties. Studies of equilibria involving Kr-O-W- and Kr?F?W-bridged species have been interpreted to suggest that stable krypton-oxygen bonds are unlikely. Raman spectra of the solid KrF2·MOF4 (M = Mo, W) adducts have been compared with those of the analogous xenon compounds and all have been interpreted in terms of covalent fluorine-bridged structures. The Raman spectra of the solid adducts XeF2·2MOF4 are also reported.
Holloway, John H.,Schrobilgen, Gary J.
p. 3363 - 3368
(2008/10/08)

Reactivity of transition metal fluorides. II. Uranium hexafluoride
Reactions have been studied between uranium hexafluoride and a series of lower fluorides of other elements. The study has also included reaction with a wide range of covalent chlorides. The reactivity of uranium hexafluoride is compared with that of the higher fluorides of d-transition elements, chromium, molybdenum, and tungsten, and considered in the light of uranium as an f-transition element.
O'Donnell,Stewart,Wilson
p. 1438 - 1441
(2008/10/08)