View source for Samarium(II) fluoride

{{Chembox
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| Section1 = {{Chembox Identifiers
|   CASNo = 	15192-17-3
|   CASNo_Ref = {{cascite|correct|CAS}}
|   PubChem = 101282799
| ChemSpiderID = 4416535
| StdInChI=1S/2FH.Sm/h2*1H;/p-2
| StdInChIKey = PBDMHCPVUGOGTK-UHFFFAOYSA-L
| SMILES = [F-].[F-].[Sm]
 }}
| Section2 = {{Chembox Properties
|   Formula = SmF<sub>2</sub>
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| Section3 = {{Chembox Hazards
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|Section4 = {{Chembox Structure
|Structure_ref = <ref name=Greis1982 />
|CrystalStruct = [[Fluorite structure]]
|SpaceGroup = Fm{{overline|3}}m (No. 225)
|LattConst_a =587.10 pm
|UnitCellFormulas = 4
|Coordination =
}}
|Section7 = {{Chembox Related
|OtherAnions = [[Samarium(II) chloride]] <br> [[Samarium(II) bromide]] <br> [[Samarium(II) iodide]]
|OtherCations = [[Europium(II) fluoride]] <br> [[Thulium(II) fluoride]] <br> [[Ytterbium(II) fluoride]]
| OtherCompounds = [[Samarium(III) fluoride]]
}}
}}

'''Samarium(II) fluoride''' is one of fluorides of [[samarium]] with a chemical formula SmF<sub>2</sub>. The compound crystalizes in the [[fluorite structure]], and is significantly [[Non-stoichiometric compound|nonstoichiometric]]. Along with [[europium(II) fluoride]] and [[ytterbium(II) fluoride]], it is one of three known rare earth difluorides, the rest are unstable.<ref name=Greis1982>{{cite book | last1=Greis | first1=Ortwin | last2=Haschke | first2=John M. | title=Handbook on the Physics and Chemistry of Rare Earths Volume 5 | chapter=Chapter 45 Rare earth fluorides | publisher=Elsevier | year=1982 | volume=5 | issn=0168-1273 | doi=10.1016/s0168-1273(82)05008-9 | pages=387–460| isbn=9780444863751 }}</ref>

== Preparation ==
Samarium(II) fluoride can be prepared by using [[samarium]] or [[hydrogen gas]] to reduce [[samarium(III) fluoride]]:<ref name=Georg>Georg Brauer (Hrsg.), unter Mitarbeit von Marianne Baudler u. a.: Handbuch der Präparativen Anorganischen Chemie. 3., umgearbeitete Auflage. Band I, Ferdinand Enke, Stuttgart 1975, {{ISBN|3-432-02328-6}}, S. 255.</ref>
:<math>\mathrm{2 \ SmF_3 + Sm \longrightarrow 3 \ SmF_2}</math>

:<math>\mathrm{2 \ SmF_3 + H_2 \longrightarrow 2 \ SmF_2 + 2 \ HF}</math>

== Properties ==

Samarium(II) fluoride is a purple to black solid. This is present in the crystal structure of the [[Cubic crystal system|cubic]] [[calcium fluoride]] type (space group Fm{{overline|3}}m; No. 225 with ''a'' = 587.7 pm).<ref>{{Cite book |last1=Ans |first1=Jean d' |url=https://books.google.com/books?id=ssy59etLaksC&pg=PA734 |title=Taschenbuch für Chemiker und Physiker |last2=Lax |first2=Ellen |date=1998 |publisher=Springer |isbn=978-3-540-60035-0 |language=de}}</ref><ref name=Georg /><ref>{{Cite web |title=mp-1206711: SmF2 (Cubic, Fm-3m, 225) |url=https://next-gen.materialsproject.org/materials/mp-1206711/ |access-date=2023-12-22 |website=Materials Project}}</ref>

==References ==
{{reflist}}


{{fluorides}}
{{samarium compounds}}
{{Lanthanide halides}}

[[Category:Samarium(II) compounds]]
[[Category:Fluorides]]
[[Category:Lanthanide halides]]
[[Category:Fluorite crystal structure]]