Hypovanadic fluoride

Hypovanadous Fluoride, vanadium difluoride, VFS, has not been isolated, but a reddish-violet solution containing it is obtained by the action of excess of hydrofluoric acid on vanadium aluminium silieide,2 VsAl2Si]3, in the absence of air. In the presence of air the solution becomes green, with evolution of hydrogen ... 

Vanadium Tetrafluoride, hypovanadic fluoride, VF4, is produced by the action of anhydrous hydrogen fluoride on the corresponding chlorine compound, VC14, at temperatures from —28° to 0° C. It is an extremely deliquescent brown powder which readily undergoes hydrolysis with water, so that it does not give rise to double salts as in the case of the trifluoride. Its density at 23° C. is 2 9749. It decomposes above 325° C., yielding a mixture of the pentafluoride and the trifluoride 1... 

Vanadyl Difluoride, VOF2, is prepared by the action of anhydrous hydrogen fluoride on vanadyl dibromide, VOBr2. It is a yellow substance. Density at 19° C., 3-3956.s A hydrated vanadyl difluoride, V0F2.a, H20, is obtained as microscopic blue crystals when hypovanadic oxide, V02, is dissolved in excess of hydrofluoric acid and the solution concentrated slowly over sulphuric acid.1 The following double salts have been prepared, all of which are crystalline and fairly stable —5... 

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