Cerium(III) iodide, with the chemical formula CeI3, is an inorganic compound composed of the rare-earth metal cerium and the halogen iodine. It is part of a group of compounds known as cerium(III) salts, where cerium is in its +3 oxidation state.

Properties of Cerium(III) Iodide:

• Appearance: Cerium(III) iodide is a solid that can vary in color depending on its hydration state and purity. Anhydrous cerium(III) iodide is a pale yellow solid, while hydrated forms may appear greenish or brownish.
• Solubility: It is sparingly soluble in water but more soluble in organic solvents.
• Crystal Structure: Cerium(III) iodide has a layered crystal structure.

Preparation and Reactions: Cerium(III) iodide can be prepared by reacting cerium metal or cerium(III) oxide with hydrogen iodide gas:

Ce + 3HI → CeI3 + 3/2H2

Like other cerium(III) salts, cerium(III) iodide can undergo various reactions with other compounds, forming different cerium-based compounds with unique properties.

Applications: Cerium(III) iodide itself does not have significant commercial applications, but it can serve as a starting material in the synthesis of other cerium compounds or cerium-doped materials with specific uses. Cerium-based materials find applications in catalysts, optical devices, scintillators, and glass manufacturing, among others, due to their unique optical and electronic properties.

Safety Considerations: As with all chemicals, cerium(III) iodide should be handled with care, and safety precautions should be followed. It is essential to consult the Material Safety Data Sheet (MSDS) for specific safety information.