Uranous Oxyfluoride, UOF₂

Uranous Oxyfluoride, UOF₂, is formed as a fine green precipitate when hydrofluoric acid acts on urano-uranic oxide. A solution of uranyl formate in formic acid, partly reduced by exposure to sunlight, yields, on addition of hydrofluoric acid, a precipitate of composition UOF₂.2H₂O. A green double salt, of composition UOF₂.NH₄F, is obtained by electrolysing a solution of uranyl ammonium carbonate containing excess of hydrofluoric acid.

When uranous fluoride is dissolved in a solution of ammonium oxalate a dark green liquid results, which exhibits a violet fluorescence and deposits on evaporation crystals of the double salt UF₄.2(NH₄)₂C₂O₄.4H₂O.