Tungsten and Fluorine

Tungsten forms with fluorine the binary compounds WFe, WF5, and WF4 while the 

PR The direct florination of tungsten in a flowing system at 350-400 °C is the most convenient procedure W + 3F2 - WF.  

Tungsten also reacts with CIF, CIF3, and BrF3 to form WFe- WO3 reacts with HF, BrF3, and SF4 to WFg. 

Soluble in benzene and cyclohexane (bright red), in dioxane (pale red), and in ether (violet-brown). It is very reactive, attacks most metals, erodes glass slowly in the absence of moisture, but rapidly in the presence of moisture. 

A WFe is today widely used by the semiconductor industry in the manufacture of 

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Tungsten and fluorine react at ordinary temjjeratures with production of a volatile, white crystalline conijround wlrich is decomposed by water. ... 

Fluorination of tungsten and rhenium produces tungsten hexafluoride, WF, and rhenium hexafluoride [10049-17-9J, ReF, respectively. These volatile metal fluorides are used in the chemical vapor deposition industry to produce metal coatings and intricately shaped components (see Thin films,... 

J. Henri Debray, 1827-1888. French chemist who collaborated with Henn Sainte-Claire Deville at the ficole Nor-male Sup rieure in researches on gaseous dissociation. He also investigated beryllium, molybdenum, tungsten, and the metals of the platinum group, and made contributions to synthetic mineralogy, It was In Debray s laboratory that Moissan liberated fluorine. 

When a cesium atom is adsorbed on a tungsten surface, level A is higher than level D (Fig. 6) and the desorption of the cesium is in ionic form, provided that no external electric fields are used that will force atoms to evaporate. The potential curves of Fig. 6 are completely comparable to the formation of the ionic molecule of CsF from the atoms of cesium and fluorine (Fig. 7). 

Fig. 13 is a drawing of electron-domain models of some Group VI hexafluorides. Open circles represent the electron-pairs of four of the six bonds to fluorine atoms in a Lewis, single-bond formulation of these molecules. Solid circles represent the atomic cores of oxygen, sulfur, selenium, tellurium, tungsten, and uranium (core radii, in hundreths of A, 9, 29, 42, 56, 62, and 80 2>, respectively). These hexafluorides are, in order, non-existent, extra-ordinarily unreactive, hydrolyzed slowly, hydrolyzed completely at room temperature in 24 hours, hydrolyzed readily, and hydrolyzed very rapidly. 

The design of transition metal complexes capable of C—F bond activation for the functionalization of fluorocarbons has attracted attention recently. It has been known for several years that oxidative addition of an aromatic C—F bond takes place at tungsten(O) to yield stable tungsten(II) metallacycles, the cleaved carbon and fluorine atoms both finishing up bound to the metal centre (Eqn. (2)) [34-36]. 

N. Bartlett and P. L. Robinson, Fluorination of the Trioxides of Chromium, Molybdenum, Tungsten and Uranium by Selenium Tetrafluoride, J. Chem. Soc. (1961) 3549-3550. 

O Hare and Hubbard (7) determined the enthalpy of formation, A H (WFg, g, 298.15 K) of tungsten in fluorine in a bomb calorimeter. This value is adopted in the tabulation. 

Tung4ten(or Wolfram) Hexafluoride, WF, mw 297.86 colorless gas or It ycl liquid toxic sp gr(liq) 3.44, fr p 2.5° bp 19-5° Can be prepd by direct fluorination of powdered tungsten, followed by distillation under pressure. Used for vapor phase deposition of tungsten and as fluorinating agent Refs 1) Gmelin-Kraut Syst Number 54(1933), 155 2) Lange (1961), 32 4 3) CondChem-... 

BICHROMATE of POTASH (7778-50-9). Noncombustible, but many chemical reactions can cause fire and explosions. A powerful oxidizer. Violent reaction with many substances, including combustible materials, reducing agents, organic materials, finely divided metals, ammonium nitrate, ammonium perchlorate, fluorine, hydrazine, hydrazinium nitrate, hydrox-ylamine, iron powder, nitric acid, potassium iodide, sodium borohydride, sodium bromide, sodium tetraborate and its decahydrate, tungsten and zirconium dusts. Mixture with sulfuric acid forms chromic acid. Incompatible with ethylene glycol, iron, tungsten. 

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