Actinium(III) fluoride (AcF₃) is an

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

, a salt of

actinium Actinium is a chemical element; it has chemical symbol, symbol Ac and atomic number 89. It was discovered by Friedrich Oskar Giesel in 1902, who gave it the name ''emanium''; the element got its name by being wrongly identified with a substa ...

and

fluorine Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...

Synthesis

Actinium fluoride can be prepared in solution or by a solid-state reaction. In the first method, actinium hydroxide is treated with

hydrofluoric acid Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colorless, acidic and highly corrosive. A common concentration is 49% (48–52%) but there are also stronger solutions (e.g. 70%) and pure HF has a boiling p ...

and the product precipitates: : In the solid-state reaction, actinium metal is treated with

hydrogen fluoride Hydrogen fluoride (fluorane) is an Inorganic chemistry, inorganic compound with chemical formula . It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid. It is the principal industrial source of fluori ...

gas at 700 °C in a platinum crucible.Meyer, Gerd and Morss, Lester R. (1991) ''Synthesis of lanthanide and actinide compounds.'' Springer. . pp. 87–88

Properties

Actinium fluoride is a white solid that reacts with ammonia at 900–1000 °C to yield an actinium oxyfluoride: : While lanthanum oxyfluoride is easily formed by heating

lanthanum fluoride Lanthanum trifluoride is a refractory ionic compound of lanthanum and fluorine. The chemical formula is . The LaF3 structure Bonding is ionic with lanthanum highly coordinated. The cation sits at the center of a trigonal prism. Nine fluorine ...

in air, a similar treatment merely melts actinium fluoride and does not yield AcOF.

References

{{Authority control Actinium compounds Fluorides Actinide halides