Samarium(III) fluoride

Samarium(III) fluoride
Names
	IUPAC name samarium(III) fluoride
	Other names samarium trifluoride; trifluorosamarium
Identifiers
CAS Number	13765-24-7 ;
3D model (JSmol)	Interactive image;
ChemSpider	75536 ;
ECHA InfoCard	100.033.956
EC Number	237-367-3;
PubChem CID	83714;
CompTox Dashboard (EPA)	DTXSID8065616 ;
	InChI InChI=1S/3FH.Sm/h31H;/q;;;+3/p-3 Key: OJIKOZJGHCVMDC-UHFFFAOYSA-K ; InChI=1/3FH.Sm/h31H;/q;;;+3/p-3 Key: OJIKOZJGHCVMDC-DFZHHIFOAV;
	SMILES F[Sm](F)F;
Properties
Chemical formula	SmF3
Molar mass	207.36 g/mol
Appearance	Yellow odorless powder
Density	6.6 g/cm3 at 20 °C
Melting point	1,306 °C (2,383 °F; 1,579 K)
Boiling point	2,427 °C (4,401 °F; 2,700 K)
Solubility in water	Insoluble
Structure
Crystal structure	Orthorhombic, oP16, SpaceGroup = Pnma, No. 62
Related compounds
Other anions	Samarium(III) chloride; Samarium(III) bromide; Samarium(III) iodide
Other cations	Samarium(II) fluoride
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H311, H315, H319, H331
Precautionary statements	P261, P264, P270, P271, P280, P301+P310, P302+P352, P304+P340, P305+P351+P338, P311, P312, P321, P322, P330, P332+P313, P337+P313, P361, P362, P363, P403+P233, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Samarium(III) fluoride (Sm F₃) is a slightly hygroscopic solid fluoride. Conditions/substances to avoid are: open flame, moisture, strong acids.

Preparation

Samarium(III) fluoride can be obtained by reacting SmCl₃ or Sm₂(CO₃)₃ with 40% hydrofluoric acid:^[1]

SmCl₃ + 3 HF → SmF₃↓ + 3 HCl

Sm₂(CO₃)₃ + 6 HF → 2 SmF₃ + 3 H₂O + 3 CO₂↑

Samarium(III) fluoride can also be produced by hydrothermal reaction of samarium nitrate and sodium fluroborate at 200 °C.^[2]

Properties

Chemical

Samarium(III) fluoride reacts with some reducing agents at high temperatures to obtain samarium(II) fluoride:

{\mathsf {4SmF_{3}+C\ {\xrightarrow {2000^{o}C}}\ 4SmF_{2}+CF_{4}}}

{\mathsf {2SmF_{3}+Sm\ {\xrightarrow {1800^{o}C}}\ 3SmF_{2}}}

Physical

At room temperature, samarium(III) fluoride has orthorhombic structure with space group Pnma – β-YF₃ type with lattice constants a = 666,9 pm, b = 705,9 pm, c = 440,5 pm. Above 495 °C, it has the rhombohedral LaF₃ structure (space group P3cl) – with lattice constants a = 707, c = 724 pm.^[3]

References

^ 王亚军, 刘前, 索全伶, 等. 稀土氟化物的沉淀方法及组成研究[J]. 稀土, 2000, 21(1):14-18.
^ 孙元平, 贾佩云, 王芳, 等. 水热条件下稀土氟化物形貌的规律性生长[J]. 中国陶瓷, 2013(6).
^ Rotereau, K; Daniel, Ph; Desert, A; Gesland, J Y (1998-02-16). "The high-temperature phase transition in samarium fluoride, : structural and vibrational investigation". Journal of Physics: Condensed Matter. 10 (6): 1431–1446. Bibcode:1998JPCM...10.1431R. doi:10.1088/0953-8984/10/6/026. ISSN 0953-8984. S2CID 250841162.