Vanadium Oxytrifluoride, VOF₃

Vanadium Oxytrifluoride, VOF₃, is obtained by the action of hydrogen fluoride on the corresponding chlorine compound, VOCl₃. It is also formed when vanadous fluoride is heated to redness in oxygen. It is a yellowish-white, extremely hygroscopic substance, readily soluble in water. Its density at 20.5° C. is 2.4591. When heated to 132° C. it undergoes partial decomposition with formation of vanadium pentoxide. The following double salts of vanadium oxytrifluoride are known: 2VOF₃.3NH₄F.H₂O, 2VOF₃.3KF, VOF₃.2KF, VOF₃.VF₅. 4KF, and 2VOF₃.3KF.HF. These double salts are white, crystalline compounds; they are stable in the air, but undergo hydrolysis in solution to form addition compounds of vanadium dioxyfluoride, VO₂F.