VF4 + 2NH4F + H2O → (NH4)2[V(H2O)OF4] + 2HF
Vanadium(IV), fluoride react with ammonium fluoride and water to produce ammonium tetrafluorooxoaquavanadate(IV) and hydrogen fluoride. Ammonium fluoride - saturated solution. This reaction slowly takes place at a temperature near 0°C.