Barium Tetraiodomercurate

Barium tetraiodomercurate is a chemical compound with the formula BaHgI4. It consists of barium cations (Ba2+) and tetraiodomercurate anions (HgI42-). The compound is a yellow-orange crystalline solid that is sparingly soluble in water.

Barium tetraiodomercurate can be synthesized by reacting barium iodide (BaI2) with mercury(II) iodide (HgI2) in a 1:2 molar ratio in water or ethanol solution. The resulting product is typically purified by recrystallization to remove impurities.

The tetraiodomercurate anion (HgI42-) is an example of a polyatomic ion, which consists of four iodine atoms bonded to a central mercury atom. This anion has a tetrahedral geometry and is negatively charged, which balances the positive charge of the barium cation in BaHgI4.

Barium tetraiodomercurate has several applications in chemistry and materials science, including its use as a precursor for the synthesis of other mercury-containing compounds and as a starting material for the preparation of mercury-based films and coatings. It is also used in the synthesis of novel nonlinear optical materials and as a reagent in organic synthesis reactions. However, it should be handled with care due to its toxicity and potential environmental hazards.