Actinium(III) fluoride

Actinium(III) fluoride (AcF₃) is an inorganic compound, a salt of actinium and fluorine.

Actinium fluoride

Crystal structure
Names
Other names Actinium(III) fluoride Actinium trifluoride
Identifiers
CAS Number	33689-80-4 Y
3D model (JSmol)	Interactive image
PubChem CID	101943120
InChI InChI=1S/Ac.3FH/h;3*1H/q+3;;;/p-3 Y InChI=1/Ac.3FH/h;3*1H/q+3;;;/p-3
SMILES F[Ac](F)F
Properties
Chemical formula	AcF3
Molar mass	284 g/mol[1]
Appearance	white, crystalline solid
Density	7.88 g/cm3[1]
Structure
Crystal structure	Rhombohedral, hR24
Space group	P3c1, No. 165[2]
Lattice constant	a = 0.741 nm, c = 0.755 nm
Lattice volume (V)	0.35902
Formula units (Z)	6
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

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 and the product precipitates:^[3]

${\displaystyle {\ce {Ac(OH)3 + 3HF -> AcF_3(v) + 3H2O}}}$

In the solid-state reaction, actinium metal is treated with hydrogen fluoride gas at 700 °C in a platinum crucible.^[4][5]

Properties

Actinium fluoride is a white solid that reacts with ammonia at 900–1000 °C to yield an actinium oxyfluoride:

${\displaystyle {\ce {AcF3 + 2NH3 + H2O -> AcOF + 2NH4F}}}$

While lanthanum oxyfluoride is easily formed by heating lanthanum fluoride in air, a similar treatment merely melts actinium fluoride and does not yield AcOF.^[4][5]

References

1. Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.44. ISBN 1-4398-5511-0.
2. Zachariasen, W. H. (1949). "Crystal chemical studies of the 5f-series of elements. XII. New compounds representing known structure types". Acta Crystallographica. 2 (6): 388–390. Bibcode:1949AcCry...2..388Z. doi:10.1107/S0365110X49001016.
3. Haire, Richard G. (2006). "Actinium". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. p. 36. ISBN 1-4020-3555-1.
4. Fried, Sherman; Hagemann, French; Zachariasen, W. H. (1950). "The Preparation and Identification of Some Pure Actinium Compounds". Journal of the American Chemical Society. 72 (2): 771. doi:10.1021/ja01158a034.
5. Meyer, Gerd and Morss, Lester R. (1991) Synthesis of lanthanide and actinide compounds. Springer. ISBN 0-7923-1018-7. pp. 87–88