Silver(I) fluoride (AgF), also known as argentous fluoride and silver monofluoride, is a compound of silver and fluorine. It is a ginger-coloured solid, melting point 435 °C, which blackens on exposure to moist air. Unlike other silver halides such as silver chloride, it is soluble in water to the extent of 1.8 kg/L, and it even has some solubility in acetonitrile. AgF is made from silver(I) carbonate and hydrofluoric acid.
Silver(I) fluoride finds most application in organofluorine chemistry for addition of fluoride across multiple bonds. For example, AgF adds to perfluoroalkenes in acetonitrile to give perfluoroalkylsilver(I) derivatives: RFCF=CF2 + AgF → RFCF(CF3)Ag.
Silver also forms a higher fluoride, silver(II) fluoride, and a lower fluoride, silver subfluoride.