Editing Europium (section)

==Compounds==
{{Main article|Europium compounds}}
[[File:Eu-sulfate.jpg|upright=0.9|thumb|right|Europium(III) sulfate, Eu<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>]]
[[File:Eu-sulfate-luminescence.jpg|upright=0.9|thumb|right|Europium(III) sulfate fluorescing red under ultraviolet light]]
Europium compounds tend to exist in a trivalent oxidation state under most conditions. Commonly these compounds feature Eu(III) bound by 6–9 oxygenic ligands. The Eu(III) sulfates, nitrates and chlorides are soluble in water or polar organic solvents. Lipophilic europium complexes often feature [[Acetylacetone|acetylacetonate]]-like ligands, such as [[Eufod|EuFOD]].

===Halides===
Europium metal reacts with all the halogens:
:2 Eu + 3 X<sub>2</sub> → 2 EuX<sub>3</sub> (X = F, Cl, Br, I)
This route gives white europium(III) fluoride (EuF<sub>3</sub>), yellow [[europium(III) chloride]] (EuCl<sub>3</sub>), gray<ref name="Bromide book">{{cite book|last1=Phillips|first1=Sidney L.|last2=Perry|first2=Dale L.|title=Handbook of inorganic compounds|date=1995|publisher=CRC Press|location=Boca Raton|isbn=9780849386718|page=159}}</ref> [[europium(III) bromide]] (EuBr<sub>3</sub>), and colorless europium(III) iodide (EuI<sub>3</sub>). Europium also forms the corresponding dihalides: yellow-green europium(II) fluoride (EuF<sub>2</sub>), colorless [[europium(II) chloride]] (EuCl<sub>2</sub>) (although it has a bright blue fluorescence under UV light),<ref name=HowellEuCl2>{{cite journal |last1=Howell |first1=J.K. |last2=Pytlewski |first2=L.L. |title=Synthesis of divalent europium and ytterbium halides in liquid ammonia |journal=Journal of the Less Common Metals |date=August 1969 |volume=18 |issue=4 |pages=437–439 |doi=10.1016/0022-5088(69)90017-4}}</ref> colorless [[europium(II) bromide]] (EuBr<sub>2</sub>), and green europium(II) iodide (EuI<sub>2</sub>).<ref name="Holleman">Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. {{ISBN|0-12-352651-5}}.</ref>

===Chalcogenides and pnictides===
Europium forms stable compounds with all of the chalcogens, but the heavier chalcogens (S, Se, and Te) stabilize the lower oxidation state. Three [[oxide]]s are known: europium(II) oxide (EuO), [[europium(III) oxide]] (Eu<sub>2</sub>O<sub>3</sub>), and the [[mixed-valency|mixed-valence]] oxide Eu<sub>3</sub>O<sub>4</sub>, consisting of both Eu(II) and Eu(III). Otherwise, the main chalcogenides are [[europium(II) sulfide]] (EuS), europium(II) selenide (EuSe) and europium(II) telluride (EuTe): all three of these are black solids. Europium(II) sulfide is prepared by sulfiding the oxide at temperatures sufficiently high to decompose the Eu<sub>2</sub>O<sub>3</sub>:<ref>{{cite book|doi = 10.1002/9780470132418.ch15|chapter = Europium (II) Sulfide|title = Inorganic Syntheses|date = 1967|last1 = Archer|first1 = R. D.|last2 = Mitchell|first2 = W. N.|last3 = Mazelsky|first3 = R.|isbn = 978-0-470-13241-8|volume = 10|pages = 77–79}}</ref>
:Eu<sub>2</sub>O<sub>3</sub> + 3 H<sub>2</sub>S → 2 EuS + 3 H<sub>2</sub>O + S
The main [[nitride]] of europium is europium(III) nitride (EuN).