Europium(III) iodide 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 ...

, a salt containing

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 ...

and

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

with the chemical formula .

Preparation

Europium metal reacts directly with iodine to form europium(III) iodide: : Hydrated europium(III) iodide can be prepared dissolving

europium(III) oxide 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 sof ...

europium(III) carbonate Europium(III) carbonate is an inorganic compound with the chemical formula Eu2(CO3)3. Preparation Europium(III) carbonate can be obtained by mixing and heating an aqueous solution of ammonium carbonate and europium(III) chloride. A saturated ca ...

hydroiodic acid Hydroiodic acid (or hydriodic acid) is a colorless liquid. It is an aqueous solution of hydrogen iodide with the chemical formula . It is a strong acid, in which hydrogen iodide is ionized completely in an aqueous solution. Concentrated aqueous ...

: : Europium powder reacts with iodine 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 ...

to form a THF

adduct In chemistry, an adduct (; alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is ...

of europium(III) iodide: : The adduct can be formulated more simply as .

Structure

Europium(III) iodide adopts the

bismuth(III) iodide Bismuth(III) iodide is the inorganic compound with the formula Bi I3. This gray-black salt is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis. Bismuth(III) iodide adopts a distin ...

(BiI₃) crystal structure type, with

octahedral In geometry, an octahedron (: octahedra or octahedrons) is any polyhedron with eight faces. One special case is the regular octahedron, a Platonic solid composed of eight equilateral triangles, four of which meet at each vertex. Many types of i ...

coordination of each Eu³⁺ ion by 6

iodide An iodide ion is I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine deficiency ...

ions.

Reactivity

Europium(III) iodide is used as the starting material for two of the main ways of preparing europium(II) iodide: 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 at 350 °C: :

Thermal decomposition Thermal decomposition, or thermolysis, is a chemical decomposition of a substance caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic ...

at 200 °C, a

disproportionation In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation state. The reverse of disproportionatio ...

reaction: : Europium(III) iodide nonahydrate, EuI₃·9H₂O, thermally decomposes to europium(II) iodide dihydrate, EuI₂·H₂O.

References

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