An octafluoride is a compound or ion with the formula or , where n, m and q are independent variables and R any substituent and M is a central element (often a metal). All of the examples listed below are with q between 1 and 4 inclusive.
Neutral octafluorides
No electrically neutral octafluorides are currently known to exist, although osmium octafluoride, , is theoretically possible. An early report of the synthesis of was much later shown to be a mistaken identification of .
Anionic octafluorides
In contrast, many anionic octafluorides are known, such as the octafluorozirconate(IV) (), octafluorotantalate(V) (), octafluoroniobate(V) (),
octafluoromolybdate(VI) (),
octafluorotungstate(VI) (),
octafluororhenate(VII) (),
octafluoroiodate(VII) (), octafluoroiridate(VII) (),
and octafluoroxenate(VI) () anions.
