EuCl2

EuCl2, or europium(II) chloride, is an inorganic salt in which europium is in the +2 oxidation state. It typically appears as a white crystalline solid that is highly hygroscopic and readily oxidizes in air to europium(III) chloride.

Preparation and handling: EuCl2 is usually obtained by selectively reducing europium(III) chloride (EuCl3) to EuCl2 under inert atmosphere, using hydrogen gas or metallic reductants such as zinc. It can also be generated in situ by reduction of EuCl3 in solution or by controlled preparation from europium metal and chlorine followed by reduction. In aqueous media, Eu2+ forms solvated complexes and is prone to oxidation by air or dissolved oxygen.

Properties and reactivity: In solution, Eu2+ is a relatively strong reducing agent; its presence gives EuCl2 solutions reducing capabilities toward certain organic substrates and metal ions, though Eu2+ is easily reoxidized to Eu3+ by oxygen. The solid and its solutions are typically moisture- and air-sensitive, and storage under inert atmosphere or in a glovebox is common. EuCl2 can form various hydrates or coordination complexes in the solid state or in coordinating solvents.

Uses: EuCl2 serves as a source of europium(II) for materials synthesis, as a precursor to other europium compounds, and in some reductive transformations in organic and inorganic chemistry. It is also of interest in research on magnetic materials and rare-earth chemistry.

Safety: Europium salts are of relatively low general toxicity, but EuCl2 should be handled with care. It is moisture- and air-sensitive, and exposure to dust, skin, or eyes should be minimized. Appropriate ventilation and personal protective equipment are recommended.