Magnesium iodide is the name of the compound with the formula MgI2 and its various hydrates MgI2(H2O)x. These salts are typically ionic halides and are highly soluble in water.
Magnesium iodide has few commercial uses, but it is used in the preparation of synthetic organic compounds.
Magnesium iodide can be prepared from magnesium oxide, magnesium hydroxide and magnesium carbonate by hydroiodic acid treatment: [3]

MgO + 2 HI ? MgI2 + H2O
Mg(OH)2 + 2 HI ? MgI2 + 2 H2O
MgCO3 + 2 HI ? MgI2 + CO2 + H2O

Magnesium iodide is stable at high temperature in a hydrogen atmosphere, but decomposes in air at normal temperature, releasing elemental iodine and turning brown. When heated in air, it completely decomposes to magnesium oxide. [4]

Another way to prepare MgI2 is to mix powdered elemental iodine and magnesium metal. In order to obtain anhydrous MgI2, the reaction should be carried out in a strictly anhydrous atmosphere; anhydrous ether can be used as a solvent.

The use of magnesium iodide in the Baylis-Hillman reaction tends to produce (Z)-vinyl compounds. [5]
Magnesium iodide formula, we also know its name is diiodide magnesium formula. It is an inorganic salt that we can easily find in seawater. Additionally, it is a chemical that contains significant amounts of hydrates, which are generally highly water-soluble ionic halides.
The chemical formula of magnesium iodide is ????????????2. Furthermore, I exists in various forms such as ????????????2 (anhydrous), ????????????2?6????2???? (six water), ????????????2?8????2???? (octahydrate).

The molar mass of each form is: 278.1139 g/mol for anhydrous magnesium iodide, 386.2005 g/mol for magnesium iodide hexahydrate, and 422.236 g/mol for magnesium iodide octahydrate. Structurally, the magnesium cation ????????2+ reacts with the iodide anion ????2+.
It exists in anhydrous form with hexagonal crystal structure, monoclinic structure in hexahydrate form and orthorhombic structure in octahydro form.
The emergence of magnesium iodide
In nature, it occurs in sea salt and is a common inorganic salt. Typically, most volumes, nanopowders, submicron and high-purities are readily available. Scientists prepare them in laboratories.

Preparation of magnesium iodide
We can prepare magnesium iodide by treating magnesium oxide and magnesium carbonate with hydroiodic acid. The response is:

????????????+?????????????????????2+????2????
????????????????3+2?????????????????????2+????????2+????2????
The reaction of magnesium iodide
Stable at high temperature under hydrogen atmosphere. However, it decomposes in air at normal or room temperature, releasing elemental iodine and turning brown. Also, when we heat it in air, it completely breaks down the magnesium oxide.

Another way to prepare ????????????2 is to mix powdered elemental iodine and metallic magnesium. Anhydrous magnesium iodide ????????????2 can be obtained, but this reaction needs to be carried out in a strictly anhydrous atmosphere, for which we can use dry ether as a solvent.

Properties of magnesium iodide
It appears as a white crystalline solid with no odor. The density of its different forms is: the density of anhydrous solid is 4.43????/????????3, the density of hexahydrate solid is 2.353????/????????3, and the density of octahydrate solid is 2.098????/????????3.