Cerium(III) fluoride

Cerium(III) fluoride (or cerium trifluoride), CeF₃, is an ionic compound of the rare earth metal cerium and fluorine.

Cerium(III) fluoride

Names
IUPAC name Cerium(III) fluoride
Other names Cerium trifluoride
Identifiers
CAS Number	7758-88-5 Y
ChemSpider	22865
ECHA InfoCard	100.028.947
EC Number	231-841-3
PubChem CID	24457
UNII	1GCT2G09AN Y
CompTox Dashboard (EPA)	DTXSID8052516
Properties
Chemical formula	CeF3
Molar mass	197.12 g/mol
Density	6.16 g/cm3 (at 20 °C)
Melting point	1,460 °C (2,660 °F; 1,730 K)[1]
Related compounds
Related compounds	Lanthanum trifluoride
Hazards
GHS labelling:
Pictograms
NFPA 704 (fire diamond)	3 0 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

It appears as a mineral in the form of fluocerite-(Ce) - a very rare mineral species related mainly to pegmatites and rarely to oxidation zones of some polymetallic ore deposits.^[2][3] CeF₃ may be used as a Faraday rotator material in the visible, near-infrared and mid-infrared spectral range.^[4][5]

Structure

The crystal structure of cerium(III) fluoride is described as the LaF₃ or tysonite structure.^[6] It contains 9-coordinate cerium ions that adopt an approximately tricapped trigonal prismatic coordination geometry,^[7] although it can be considered 11-coordinate if two more distant fluorides are considered part of the cerium coordination environment.^[6] The three crystallographically independent fluoride ions are 3-coordinate and range in geometry from trigonal planar to pyramidal.^[6]

Coordination in cerium(III) fluoride^[8]

Cerium coordination	Fluorine F1 coordination	Fluorine F2 coordination	Fluorine F3 coordination