Magnesium iodide

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Magnesium iodide
IUPAC name
Magnesium iodide
3D model (JSmol)
ECHA InfoCard 100.030.738 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 233-825-1
PubChem CID
  • InChI=1S/2HI.Mg/h2*1H;/q;;+2/p-2 X mark.svgN
  • InChI=1/2HI.Mg/h2*1H;/q;;+2/p-2
  • I[Mg]I
  • [Mg+2].[I-].[I-]
MgI2 (anhydrous)
MgI2.6H2O (hexahydrate)
MgI2.8H2O (octahydrate) [1]
Molar mass 278.1139 g/mol (anhydrous)
386.2005 g/mol (hexahydrate)
422.236 g/mol (octahydrate)
Appearancewhite crystalline solid
Odor odorless
Density 4.43 g/cm3 (anhydrous solid)
2.353 g/cm3 (hexahydrate solid)
2.098 g/cm3 (octahydrate solid)
Melting point 637 °C (1,179 °F; 910 K)(anhydrous, decomposes)
41 °C (octahydrate, decomposes)
54.7 g/100 cm3 (anhydrous, 0 °C)
148 g/100 cm3 (anhydrous, 18 °C) [2]
81 g/100 cm3 (octahydrate, 20 °C)
Solubility soluble in ether, alcohol and ammonia
111.0·10−6 cm3/mol
Hexagonal (anhydrous)
Monoclinic (hexahydrate)
Orthorhombic (octahydrate)
74 J/mol K
134 J/mol K
-364 kJ/mol
GHS pictograms GHS-pictogram-exclam.svg
GHS Signal word Warning
H315, H319
NFPA 704 (fire diamond)
Related compounds
Other anions
Magnesium fluoride
Magnesium bromide
Magnesium chloride
Other cations
beryllium iodide
calcium iodide
strontium iodide
barium iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Magnesium iodide is the name for the chemical compounds with the formulas MgI2 and its various hydrates MgI2(H2O)x. These salts are typical ionic halides, being highly soluble in water.



Magnesium iodide has few commercial uses, but can be used to prepare compounds for organic synthesis.


Magnesium iodide can be prepared from magnesium oxide, magnesium hydroxide, and magnesium carbonate by treatment with hydroiodic acid: [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 heat under a hydrogen atmosphere, but decomposes in air at normal temperatures, turning brown from the release of elemental iodine. When heated in air, it decomposes completely to magnesium oxide. [4]

Another method to prepare MgI2 is mixing powdered elemental iodine and magnesium metal. In order to obtain anhydrous MgI2, the reaction should be conducted in a strictly anhydrous atmosphere; dry-diethyl ether can be used as a solvent.

Usage of magnesium iodide in the Baylis-Hillman reaction tends to give (Z)-vinyl compounds. [5]

Related Research Articles

Inorganic chemistry deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. The distinction between the two disciplines is far from absolute, as there is much overlap in the subdiscipline of organometallic chemistry. It has applications in every aspect of the chemical industry, including catalysis, materials science, pigments, surfactants, coatings, medications, fuels, and agriculture.

Iodine Chemical element with atomic number 53

Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black non-metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius. However, it readily sublimes with gentle heat, resulting in a widespread misconception even taught in some science textbooks that it does not melt at standard pressure. The element was discovered by the French chemist Bernard Courtois in 1811, and was named two years later by Joseph Louis Gay-Lussac, after the Greek ἰώδης "violet-coloured".

Magnesium sulfate Chemical compound

Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula MgSO
, consisting of magnesium cations Mg2+
and sulfate anions SO2−
. It is a white crystalline solid, soluble in water but not in ethanol.

In chemistry, halogenation is a chemical reaction that involves the addition of one or more halogens to a compound or material. The pathway and stoichiometry of halogenation depends on the structural features and functional groups of the organic substrate, as well as on the specific halogen. Inorganic compounds such as metals also undergo halogenation.

Zinc chloride

Zinc chloride is the name of chemical compounds with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. This white salt is hygroscopic and even deliquescent. Samples should therefore be protected from sources of moisture, including the water vapor present in ambient air. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

Neodymium(III) chloride or neodymium trichloride is a chemical compound of neodymium and chlorine with the formula NdCl3. This anhydrous compound is a mauve-colored solid that rapidly absorbs water on exposure to air to form a purple-colored hexahydrate, NdCl3·6H2O. Neodymium(III) chloride is produced from minerals monazite and bastnäsite using a complex multistage extraction process. The chloride has several important applications as an intermediate chemical for production of neodymium metal and neodymium-based lasers and optical fibers. Other applications include a catalyst in organic synthesis and in decomposition of waste water contamination, corrosion protection of aluminium and its alloys, and fluorescent labeling of organic molecules (DNA).

Aluminium chloride Chemical compound

Aluminium chloride (AlCl3), also known as aluminium trichloride, describe compounds with the formula AlCl3(H2O)n (n = 0 or 6). They consist of aluminium and chlorine atoms in a 1:3 ratio, and one form also contains six waters of hydration. Both are white solids, but samples are often contaminated with iron(III) chloride, giving a yellow color.

Hydrazoic acid Unstable and toxic chemical compound

Hydrazoic acid, also known as hydrogen azide or azoimide, is a compound with the chemical formula HN3. It is a colorless, volatile, and explosive liquid at room temperature and pressure. It is a compound of nitrogen and hydrogen, and is therefore a pnictogen hydride. It was first isolated in 1890 by Theodor Curtius. The acid has few applications, but its conjugate base, the azide ion, is useful in specialized processes.

Hydrogen iodide

Hydrogen iodide (HI) is a diatomic molecule and hydrogen halide. Aqueous solutions of HI are known as hydroiodic acid or hydriodic acid, a strong acid. Hydrogen iodide and hydroiodic acid are, however, different in that the former is a gas under standard conditions, whereas the other is an aqueous solution of the gas. They are interconvertible. HI is used in organic and inorganic synthesis as one of the primary sources of iodine and as a reducing agent.

Gold(III) chloride

Gold(III) chloride, traditionally called auric chloride, is a chemical compound of gold and chlorine. With the molecular formula Au2Cl6, the name gold trichloride is a simplification, referring to the empirical formula, AuCl3. The Roman numerals in the name indicate that the gold has an oxidation state of +3, which is common for gold compounds. There is also another related chloride of gold, gold(I) chloride (AuCl). Chloroauric acid, HAuCl4, the product formed when gold dissolves in aqua regia, is sometimes referred to as "gold chloride" or "acid gold trichloride". Gold(III) chloride is very hygroscopic and highly soluble in water as well as ethanol. It decomposes above 160 °C or in light.

Lithium iodide

Lithium iodide, or LiI, is a compound of lithium and iodine. When exposed to air, it becomes yellow in color, due to the oxidation of iodide to iodine. It crystallizes in the NaCl motif. It can participate in various hydrates.

Copper(I) iodide

Copper(I) iodide is the inorganic compound with the formula CuI. It is also known as cuprous iodide. It is useful in a variety of applications ranging from organic synthesis to cloud seeding.

Hydrogen telluride (tellane) is the inorganic compound with the formula H2Te. A hydrogen chalcogenide and the simplest hydride of tellurium, it is a colorless gas. Although unstable in ambient air, the gas can exist at very low concentrations long enough to be readily detected by the odour of rotting garlic at extremely low concentrations; or by the revolting odour of rotting leeks at somewhat higher concentrations. Most compounds with Te–H bonds (tellurols) are unstable with respect to loss of H2. H2Te is chemically and structurally similar to hydrogen selenide, both are acidic. The H–Te–H angle is about 90°. Volatile tellurium compounds often have unpleasant odours, reminiscent of decayed leeks or garlic.

Grignard reagent

A Grignard reagent or Grignard compound is a chemical compound with the generic formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH
and phenylmagnesium bromide (C
. They are a subclass of the organomagnesium compounds.

Carbon tetraiodide

Carbon tetraiodide is a tetrahalomethane with the molecular formula CI4. Being bright red, it is a relatively rare example of a highly colored methane derivative. It is only 2% by weight carbon, although other methane derivatives are known with still less carbon.

Aluminium iodide Chemical compound

Aluminium iodide is a chemical compound containing aluminium and iodine. Invariably, the name refers to a compound of the composition AlI
, formed by the reaction of aluminium and iodine or the action of HI on Al metal. The hexahydrate is obtained from a reaction between metallic aluminum or aluminum hydroxide with hydrogen iodide or hydroiodic acid. Like the related chloride and bromide, AlI
is a strong Lewis acid and will absorb water from the atmosphere. It is employed as a reagent for the scission of certain kinds of C-O and N-O bonds. It cleaves aryl ethers and deoxygenates epoxides.

Calcium iodates are inorganic compound composed of calcium and iodate anion. Two forms are known, anhydrous Ca(IO3)2 and the hexahydrate Ca(IO3)2(H2O). Both are colourless salts that occur naturally as the minerals called lautarite and bruggenite, respectively. A third mineral form of calcium iodate is dietzeite, a salt containing chromate with the formula Ca2(IO3)2CrO4.

Cobalt(II) iodide

Cobalt(II) iodide or cobaltous iodide are the inorganic compounds with the formula CoI2 and the hexahydrate CoI2(H2O)6. These salts are the principal iodides of cobalt.

Magnesium oxalate

Magnesium oxalate is an organic compound comprising a magnesium cation with a 2+ charge bonded to an oxalate anion. It has the chemical formula MgC2O4. Magnesium oxalate is a white solid that comes in two forms: an anhydrous form and a dihydrate form where two water molecules are complexed with the structure. Both forms are practically insoluble in water and are insoluble in organic solutions.

Iron(II) iodide is an inorganic compound with the chemical formula FeI2. It is used as a catalyst in organic reactions.


  1. Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, p. 240, ISBN   0-8493-8671-3 , retrieved 2007-12-09
  2. Magnesium Iodide MSDS at AlfaAesar [ permanent dead link ]
  3. Patnaik, Pradyot (2003), Handbook of Inorganic Chemicals, McGraw-Hill Professional, pp. 527–528, ISBN   0-07-049439-8 , retrieved 2007-12-09
  4. Wilsmore, N. T. M. (1891). "Note on Magnesium Iodide". In James Hector (ed.). Report of the Third Meeting of the Australasian Association for the Advancement of Science. Sydney: The Association. p. 116. Retrieved 2007-12-09.
  5. Tietze, Lutz-Friedjan; Brasche, Gordon; Gericke, Kersten (2006), "Domino Reactions in Organic Synthesis", Chemical Reviews, Wiley-VCH, 96 (1): 115–136, doi:10.1021/cr950027e, ISBN   3-527-29060-5, PMID   11848746 , retrieved 2007-12-09