Europium(III) chloride is an
inorganic compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...
with the formula EuCl
3. 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 or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...
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 ...
, EuCl
3·6H
2O, 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 spe ...
produces hydrated europium chloride (EuCl
3·6H
2O). This salt cannot be rendered anhydrous by heating. Instead one obtains an
oxychloride
In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula , where X = fluorine (F), chlor ...
.
Anhydrous EuCl
3 is often prepared by the "
ammonium chloride route," starting from either Eu
2O
3 or hydrated europium chloride (EuCl
3·6H
2O) by heating carefully to 230 °C. These methods produce (NH
4)
2 5">uCl5
:10 NH
4Cl + Eu
2O
3 → 2 (NH
4)
2 5">uCl5 + 6 NH
3 + 3 H
2O
:EuCl
3·6H
2O + ''2'' NH
4Cl → (NH
4)
2 5">uCl5+ 6 H
2O
The pentachloride
decomposes thermally according to the following equation:
: (NH
4)
2 5">uCl5 → 2 NH
4Cl + EuCl
3
The thermolysis reaction proceeds via the intermediary of (NH
4)
2Cl7">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, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding a ...
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 ...
and requires a period at reflux.
: EuCl
3 + 3 LiN(SiMe
3)
2 → Eu(N(SiMe
3)
2)
3 + 3 LiCl
Eu(N(SiMe
3)
2)
3 is a starting material for the more complicated
coordination complex
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...
es.
Reduction with
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
gas with heating gives EuCl
2. 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 with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture. Europium is also the softest lanth ...
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
s.
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