EuI3

EuI3, or europium triiodide, is a chemical compound consisting of europium in the +3 oxidation state coordinated to three iodide ligands. It is one of the lanthanide trihalides and is typically prepared by direct combination of europium metal with iodine at elevated temperature under inert atmosphere: 2 Eu + 3 I2 → 2 EuI3. It can also be formed by oxidation of EuI2 with iodine under suitable conditions.

In appearance, EuI3 is a dark crystalline solid that is sensitive to air and moisture. It is poorly soluble in water and readily hydrolyzes upon exposure to moisture. In donor solvents such as tetrahydrofuran (THF), EuI3 forms solvated complexes (for example, EuI3(THF)x), which are used in coordination chemistry and as precursors for other europium compounds. The solid lattice of EuI3 is generally insulating, and the compound tends to decompose upon heating to EuI2 and iodine.

EuI3 contains europium in the +3 oxidation state (4f6 configuration). The Eu3+ ion typically exhibits little to no magnetic moment in the solid state, so EuI3 is essentially non-magnetic. The compound serves as a useful reagent and precursor in synthesis of europium-containing materials, including coordination compounds and materials for luminescent applications.

Safety and handling: europium compounds are handled with standard laboratory precautions; iodides can be irritants and should be handled to avoid inhalation or ingestion. EuI3 is moisture- and air-sensitive and is typically prepared and stored under inert atmosphere.