Europium(III) chloride is an inorganic compound with the formula EuCl3. The anhydrous compound is a yellow solid. Being hygroscopic it rapidly absorbs water to form a white crystalline hexahydrate, EuCl3·6H2O, which is colourless. The compound is used in research.
Treating Eu2O3 with aqueous HCl produces hydrated europium chloride (EuCl3·6H2O). This salt cannot be rendered anhydrous by heating. Instead one obtains an oxychloride.
Anhydrous EuCl3 is often prepared by the "ammonium chloride route," starting from either Eu2O3<ref>
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</ref><ref name="EdelmannPoremba1997">Template:Cite book</ref> or hydrated europium chloride (EuCl3·6H2O) by heating carefully to 230 °C.<ref>Template:Cite journal</ref> These methods produce (NH4)2[EuCl5]:
Reduction with hydrogen gas with heating gives EuCl2. The latter has been used to prepare organometallic compounds of europium(II), such as bis(pentamethylcyclopentadienyl)europium(II) complexes.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> Europium(III) chloride can be used as a starting point for the preparation of other europiumsalts.
Structure
In the solid state, it crystallises in the UCl3 motif. The Eu centres are nine-coordinate.<ref>Template:Greenwood&Earnshaw</ref>
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