Dioxygen difluoride is a
compound of
fluorine and
oxygen with the
molecular formula . It exists as an orange solid that melts into a red liquid at . It is an extremely
strong oxidant and
decomposes into oxygen and fluorine even at at a rate of 4% per day: its lifetime at room temperature is thus extremely short. Dioxygen difluoride reacts with nearly every chemical it encounters – even ordinary ice – leading to its
onomatopoeic nickname "
FOOF" (a play on its chemical structure).