View source for Samarium(III) fluoride

{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 476999201
| ImageFile = Kristallstruktur Yttrium(III)-fluorid.png
| ImageSize = 
| IUPACName = samarium(III) fluoride
| OtherNames = samarium trifluoride<br/>trifluorosamarium
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 13765-24-7
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 75536
| InChI = 1/3FH.Sm/h3*1H;/q;;;+3/p-3
| InChIKey = OJIKOZJGHCVMDC-DFZHHIFOAV
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/3FH.Sm/h3*1H;/q;;;+3/p-3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = OJIKOZJGHCVMDC-UHFFFAOYSA-K
| EINECS = 237-367-3
| PubChem = 83714
| SMILES = F[Sm](F)F
  }}
|Section2={{Chembox Properties
| Formula = SmF<sub>3</sub>
| MolarMass = 207.36 g/mol
| Appearance = Yellow odorless powder
| Density = 6.6 g/cm<sup>3</sup> at 20 °C
| MeltingPtC = 1306
| BoilingPtC = 2427
| Solubility = Insoluble
}}
|Section3={{Chembox Structure
| CrystalStruct = [[Orthorhombic]], [[Pearson symbol|oP16]], SpaceGroup = Pnma, No. 62
}}
|Section7={{Chembox Hazards
| MainHazards = 
| GHSPictograms = {{GHS06}}{{GHS07}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|301|311|315|319|331}}
| PPhrases = {{P-phrases|261|264|270|271|280|301+310|302+352|304+340|305+351+338|311|312|321|322|330|332+313|337+313|361|362|363|403+233|405|501}}
  }}
|Section4={{Chembox Related
| OtherAnions = [[Samarium(III) chloride]]<br/>[[Samarium(III) bromide]]<br/>[[Samarium(III) iodide]]
| OtherCations = [[Samarium(II) fluoride]]
  }}
}}

'''Samarium(III) fluoride''' ([[Samarium|Sm]][[Fluorine|F<sub>3</sub>]]) is a slightly [[hygroscopic]] solid [[fluoride]]. Conditions/substances to avoid are: open [[flame]], moisture, strong [[acid]]s.

== Preparation ==

Samarium(III) fluoride can be obtained by reacting SmCl<sub>3</sub> or Sm<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub> with 40% hydrofluoric acid:<ref>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.</ref>

:{{chem2|SmCl3 + 3 HF → SmF3↓ + 3 HCl}}

:{{chem2|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.<ref>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).</ref>

== Properties ==

=== Chemical ===

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

: <math>\mathsf{ 4 SmF_3 + C \ \xrightarrow{2000^oC}\ 4 SmF_2 + CF_4 }</math>
: <math>\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-YF<sub>3</sub> type with [[lattice constant]]s ''a'' = 666,9 [[Picometer|pm]], ''b'' = 705,9 pm, ''c'' = 440,5 pm. Above 495&nbsp;°C, it has the [[rhombohedral]]  [[lanthanum fluoride|LaF<sub>3</sub>]] structure (space group ''P3cl'') – with lattice constants ''a'' = 707, ''c'' = 724 pm.<ref>{{Cite journal |last1=Rotereau |first1=K |last2=Daniel |first2=Ph |last3=Desert |first3=A |last4=Gesland |first4=J Y |date=1998-02-16 |title=The high-temperature phase transition in samarium fluoride, : structural and vibrational investigation |url=https://iopscience.iop.org/article/10.1088/0953-8984/10/6/026 |journal=Journal of Physics: Condensed Matter |volume=10 |issue=6 |pages=1431–1446 |doi=10.1088/0953-8984/10/6/026 |bibcode=1998JPCM...10.1431R |s2cid=250841162 |issn=0953-8984|url-access=subscription }}</ref>

==References==
{{reflist}}
{{Samarium compounds}}
{{fluorides}}
{{Lanthanide halides}}

[[Category:Fluorides]]
[[Category:Lanthanide halides]]
[[Category:Samarium(III) compounds]]