Europium(II) fluoride

Europium(II) fluoride is an inorganic compound with a chemical formula EuF₂. It was first synthesized in 1937.^[1]

Europium(II) fluoride

Names
IUPAC name Europium(II) fluoride
Other names Europium difluoride
Identifiers
CAS Number	14077-39-5^Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	13834724
ECHA InfoCard	100.203.721
PubChem CID	21225127
CompTox Dashboard (EPA)	DTXSID00611473
InChI InChI=1S/Eu.2FH/h;2*1H/q+2;;/p-2 Key: YLDGIMHVWSTRML-UHFFFAOYSA-L
SMILES F[Eu]F [F-].[F-].[Eu+2]
Properties
Chemical formula	EuF2
Molar mass	189.96
Appearance	dark yellowish solid^[1]
Density	6.495 g·cm^−3
Structure^[2]
Crystal structure	Fluorite structure
Space group	Fm3m (No. 225)
Lattice constant	a = 584.23 pm
Formula units (Z)	4
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301
Precautionary statements	P264, P270, P301+P310, P321, P330, P405, P501
Related compounds
Other anions	Europium(II) bromide Europium(II) chloride Europium(II) iodide
Other cations	Samarium(II) fluoride Thulium(II) fluoride Ytterbium(II) fluoride
Related compounds	Europium(III) fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Production

Europium(II) fluoride can be produced by reducing europium(III) fluoride with metallic europium or hydrogen gas.^[3]

${\displaystyle \mathrm {2\ EuF_{3}+Eu\longrightarrow 3\ EuF_{2}} }$ 

${\displaystyle \mathrm {2\ EuF_{3}+H_{2}\longrightarrow 2\ EuF_{2}+2\ HF} }$ 

Properties

Europium(II) fluoride is a bright yellowish solid with a fluorite structure.^[3]

EuF₂ can be used to dope a trivalent rare-earth fluoride, such as LaF₃, to create a vacancy-filled structure with increased conductivity over a pure crystal. Such a crystal can be used as a fluoride-specific semipermeable membrane in a fluoride selective electrode to detect trace quantities of fluoride.^[4][5]

References

1. Zhao Yongzhi, Ma Ying, Hou Shaochun, Zhang Wenjuan, Wang Jingjing, Ding Yanrong, Hao Yifan. 氟化亚铕研究现状 2022-01-14 at the Wayback Machine (lit. Research Progress of Europium(II) Fluoride). Chinese Rare Earths, 2017. 38 (5): 134-140. (in Chinese)
2. Greis, Ortwin; Haschke, John M. (1982). "Chapter 45 Rare earth fluorides". Handbook on the Physics and Chemistry of Rare Earths Volume 5. Elsevier. pp. 387–460. doi:10.1016/s0168-1273(82)05008-9. ISSN 0168-1273.
3. Georg Brauer: Handbuch der Präparativen Anorganischen Chemie. 3., umgearb. Auflage. Band I. Enke, Stuttgart 1975, ISBN 3-432-02328-6, S. 255.
4. Light, Truman S.; Cappuccino, Carleton C. (April 1975). "Determination of fluoride in toothpaste using an ion-selective electrode". Journal of Chemical Education. 52 (4): 247–250. Bibcode:1975JChEd..52..247L. doi:10.1021/ed052p247. PMID 1133123.
5. Frant, Martin S.; Ross, James W. (23 December 1966). "Electrode for Sensing Fluoride Ion Activity in Solution" (PDF). Science. 154 (3756): 1553–1555. Bibcode:1966Sci...154.1553F. doi:10.1126/science.154.3756.1553. JSTOR 1720460. PMID 5924922. S2CID 11042445.