Europium(III) chloride

Preparation

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 or hydrated europium chloride (EuCl3·6H2O) by heating carefully to 230 °C. These methods produce (NH4)2[EuCl5]:

:10 NH4Cl + Eu2O3 → 2 (NH4)2[EuCl5] + 6 NH3 + 3 H2O

:EuCl3·6H2O + 2 NH4Cl → (NH4)2[EuCl5] + 6 H2O

The pentachloride decomposes thermally according to the following equation: : (NH4)2[EuCl5] → 2 NH4Cl + EuCl3 The thermolysis reaction proceeds via the intermediary of (NH4)[Eu2Cl7].

Reactions

Europium(III) chloride is a precursor to other europium compounds. It can be converted to the corresponding metal bis(trimethylsilyl)amide via salt metathesis with lithium bis(trimethylsilyl)amide. The reaction is performed in THF and requires a period at reflux.

: EuCl3 + 3 LiN(SiMe3)2 → Eu(N(SiMe3)2)3 + 3 LiCl

Eu(N(SiMe3)2)3 is a starting material for the more complicated coordination complexes.

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. Europium(III) chloride can be used as a starting point for the preparation of other europium salts.

Structure

In the solid state, it crystallises in the UCl3 motif. The Eu centres are nine-coordinate. :[[File:Cerium bromide (space filling) 2.png|thumb|left|160px|Space-filling image of EuCl3.]]

Bibliography

References

References

1. Edelmann, F. T.. (1997). "Synthetic Methods of Organometallic and Inorganic Chemistry". Georg Thieme Verlag.
2. Taylor, M.D.. (1962). "Preparation of anhydrous lanthanide halides, especially iodides". Journal of Inorganic and Nuclear Chemistry.
3. Bradley, Donald C.. (1973). "Low co-ordination numbers in lanthanide and actinide compounds. Part I. The preparation and characterization of tris{bis(trimethylsilyl)-amido}lanthanides". Journal of the Chemical Society, Dalton Transactions.
4. Tilley, T. Don. (1980). "Divalent lanthanide chemistry. Bis (pentamethylcyclopentadienyl) europium(II) and -ytterbium(II) derivatives: crystal structure of bis (pentamethylcyclopentadienyl) (tetrahydrofuran ytterbium(II) -hemitoluene at 176 K". Inorganic Chemistry.
5. Evans, William J.. (1986). "Synthesis and x-ray crystal structure of bis(pentamethylcyclopentadienyl) complexes of samarium and europium: (C₅Me₅)₂Sm and (C₅Me₅)₂Eu". Organometallics.
6. {{Greenwood&Earnshaw