Silver subfluoride, Ag₂F

When a saturated solution of silver fluoride is heated with finely divided silver, a golden-yellow, crystalline precipitate of the composition Silver subfluoride, Ag₂F is produced. The reaction is attended by the evolution of 0.7 Cal., and the heat of formation of the subfluoride from its elements is 26.3 Cal. At 180° C. water-vapour converts the fluoride into the suboxide, Ag₄O.

The dihydrate, Ag₂F,2H₂O, is obtained in colourless octahedra by evaporating a solution of silver fluoride in absence of light, and removing excess of silver fluoride by extracting with alcohol.