Terbium(IV) fluoride

Terbium fluoride is an inorganic compound with a chemical formula TbF₄. It is a white solid that is a strong oxidizer. It is also a strong fluorinating agent, emitting relatively pure atomic fluorine when heated, rather than the mixture of fluoride vapors emitted from cobalt(III) fluoride or cerium(IV) fluoride.

Preparation

Terbium fluoride can be produced by the reaction between very pure terbium(III) fluoride and xenon difluoride, chlorine trifluoride or fluorine gas:

Properties

Terbium fluoride hydrolyzes quickly in hot water, producing terbium fluoride and terbium oxyfluoride. Heating terbium fluoride will cause it to decompose into terbium fluoride and predominantly monatomic fluorine gas.
The reaction will produce the mixed valence compound Tb₃, which has the same crystal form as Ln₃.
Terbium fluoride can oxidize cobalt trifluoride into cobalt tetrafluoride:
It can fluoronate Buckminsterfullerene|fullerene at 320–460 °C.
When terbium fluoride reacts with potassium chloride and fluorine, it can produce the mixed valence compound KTb₃F₁₂. A mixture of rubidium fluoride, aluminium fluoride and terbium fluoride produces Rb₂AlTb₃F₁₆.