Chemistry:Samarium(III) fluoride
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| Names | |
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| IUPAC name
samarium(III) fluoride
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| Other names
samarium trifluoride
trifluorosamarium | |
| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
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PubChem CID
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| Properties | |
| 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) |
| Insoluble | |
| Structure | |
| Orthorhombic, oP16, SpaceGroup = Pnma, No. 62 | |
| Related compounds | |
Other anions
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Samarium(III) chloride Samarium(III) bromide Samarium(III) iodide |
Other cations
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Samarium(II) fluoride |
| Hazards | |
| GHS pictograms |  
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| GHS Signal word | Danger |
| H301, H311, H315, H319, H331 | |
| P261, P264, P270, P271, P280, P301+310, P302+352, P304+340, P305+351+338, P311, P312, P321, P322, P330, P332+313, P337+313, P361, P362, P363, P403+233, 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   ?)
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| Infobox references | |
Samarium(III) fluoride (SmF3) 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]
- SmCl
3 + 3 HF → SmF
3↓ + 3 HCl
- Sm
2(CO
3)
3 + 6 HF → 2 SmF
3 + 3 H
2O + 3 CO
2↑
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:
- [math]\displaystyle{ \mathsf{ 4 SmF_3 + C \ \xrightarrow{2000^oC}\ 4 SmF_2 + CF_4 } }[/math]
- [math]\displaystyle{ \mathsf{ 2 SmF_3 + Sm \ \xrightarrow{1800^oC}\ 3 SmF_2 } }[/math]
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. doi:10.1088/0953-8984/10/6/026. ISSN 0953-8984. Bibcode: 1998JPCM...10.1431R. https://iopscience.iop.org/article/10.1088/0953-8984/10/6/026.
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