Silver subfluoride is the inorganic compound with the formula Ag<sub>2</sub>F. This is an unusual example of a compound where the oxidation state of silver is fractional. The compound is produced by the reaction of silver and silver(I) fluoride:
It forms small crystals with a bronze reflex and is a good conductor of electricity. On contact with water almost instant hydrolysis occurs with the precipitation of silver (Ag) powder.
Ag<sub>2</sub>F adopts the anti-CdI<sub>2</sub> crystal structure, i.e. the same structure as cadmium iodide, CdI<sub>2</sub>, but with "Ag<sup>ý+</sup>" centres in the I<sup>âÂÂ</sup> positions and F<sup>âÂÂ</sup> in the Cd<sup>2+</sup> positions. The shortest distance between silver atoms is 299.6 pm (compared to 289 pm in the metal).