Europium(III) chloride is an

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the formula EuCl₃. The

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...

compound is a yellow solid. Being

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption (chemistry), absorption or adsorption from the surrounding Natural environment, environment, which is usually at normal or room temperature. If water mol ...

it rapidly absorbs water to form a white crystalline

hexahydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

, EuCl₃·6H₂O, which is colourless. The compound is used in research.

Preparation

Treating Eu₂O₃ with aqueous

HCl HCL may refer to: Science and medicine * Hairy cell leukemia, an uncommon and slowly progressing B cell leukemia * Harvard Cyclotron Laboratory, from 1961 to 2002, a proton accelerator used for research and development * Hollow-cathode lamp, a s ...

produces hydrated europium chloride (EuCl₃·6H₂O). This salt cannot be rendered anhydrous by heating. Instead one obtains an

oxychloride In chemistry, oxohalides or oxyhalides are a group of chemical compounds with the chemical formula , where X is a halogen, and A is an element different than O and X. Known oxohalides have fluorine (F), chlorine (Cl), bromine (Br), and/or iodine ( ...

. Anhydrous EuCl₃ is often prepared by the "

ammonium chloride Ammonium chloride is an inorganic chemical compound with the chemical formula , also written as . It is an ammonium salt of hydrogen chloride. It consists of ammonium cations and chloride anions . It is a white crystalline salt (chemistry), sal ...

route," starting from either Eu₂O₃ or hydrated europium chloride (EuCl₃·6H₂O) by heating carefully to 230 °C. These methods produce (NH₄)₂ uCl₅ :10 NH₄Cl + Eu₂O₃ → 2 (NH₄)₂ uCl₅ + 6 NH₃ + 3 H₂O :EuCl₃·6H₂O + ''2'' NH₄Cl → (NH₄)₂ uCl₅+ 6 H₂O The pentachloride decomposes thermally according to the following equation: : (NH₄)₂ uCl₅ → 2 NH₄Cl + EuCl₃ The thermolysis reaction proceeds via the intermediary of (NH₄) u₂Cl₇

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 A salt metathesis reaction (also called a double displacement reaction, double replacement reaction, or double decomposition) is a type of chemical reaction in which two ionic compounds in aqueous solution exchange their component ions to form two ...

with

lithium bis(trimethylsilyl)amide Lithium bis(trimethylsilyl)amide is a lithiated organosilicon compound with the formula . It is commonly abbreviated as LiHMDS or Li(HMDS) (lithium hexamethyldisilazide - a reference to its conjugate acid HMDS) and is primarily used as a strong ...

. The reaction is performed in

THF Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water-miscible organic liquid with low viscosity. It is ma ...

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 complex A coordination complex is a chemical compound consisting of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ' ...

es. Reduction with

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

gas with heating gives EuCl₂. The latter has been used to prepare

organometallic Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and so ...

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 Europium is a chemical element; it has symbol Eu and atomic number 63. It is a silvery-white metal of the lanthanide series that reacts readily with air to form a dark oxide coating. Europium is the most chemically reactive, least dense, and soft ...

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

Structure

In the solid state, it crystallises in the UCl₃ motif. The Eu centres are nine-coordinate. :

Bibliography

References

{{Lanthanide halides Chlorides Europium(III) compounds Lanthanide halides