Tungsten hexafluoride preparation

Fluorophosphites are also among the products from reactions between (a) trimethylphosphite and tungsten hexafluoride 251), (6) alcohols and dichlorofluorophosphine 55, 67, 205), (c) phosphorus pentafluoride or trifluorophosphine and trimethylphosphite 35), and d) epoxides and trifluorophosphine in the presence of a tertiary amine 150), but these are of less importance from a preparative viewpoint. The attempted... 

Tungsten pentafluofide [19357-83-6] prepared by the reduction of the hexafluoride on a hot tungsten filament in almost quantitative yield... 

Tungsten tetrafluofide [13766-47-7] WF, is a nonvolatile, hygroscopic, reddish-brown soHd. It has been prepared in low yields by the reduction of the hexafluoride with phosphoms trifluofide in the presence of Hquid anhydrous hydrogen fluoride at room temperature (6). 

During the preparation of the hexamethoxides of rhenium, molybdenum and tungsten by co-condensation with excess tetramethoxysilane on a cold surface, simultaneous co-condensation is necessary to avoid the danger of explosion present when sequential condensation of the reactants is employed. In the latter case, the high concentrations of hexafluoride at the interface leads to violent reaction with the silane. 

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