Magnesium iodide

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Magnesium iodide
Identifiers
CAS number10377-58-9 YesY,  (anhydrous)
75535-11-4 (hexahydrate)
7790-31-0 (octahydrate)
PubChem66322
ChemSpider59700 N
Jmol-3D imagesImage 1
Properties
Molecular formulaMgI2 (anhydrous)
MgI2.6H2O (hexahydrate)
MgI2.8H2O (octahydrate)[1]
Molar mass278.1139 g/mol (anhydrous)
386.2005 g/mol (hexahydrate)
422.236 g/mol (octahydrate)
Appearancewhite crystalline solid
Odorodorless
Density4.43 g/cm³ (anhydrous solid)
2.353 g/cm³ (hexahydrate solid)
2.098 g/cm³ (octahydrate solid)
Melting point637 °C (anhydrous, decomposes)
41 °C (octahydrate, decomposes)
Solubility in water54.7 g/100 cm³ (anhydrous, 0 °C)
148 g/100 cm³ (anhydrous, 18 °C)[2]
81 g/100 cm³ (octahydrate, 20 °C)
Solubilitysoluble in ether, alcohol and ammonia
Structure
Crystal structureHexagonal (anhydrous)
Monoclinic (hexahydrate)
Orthorhombic (octahydrate)
Hazards
R-phrasesR36 R38 R42 R43 R61
S-phrasesS22 S36/37/39 S45 S53[3]
NFPA 704
NFPA 704.svg
1
3
1
Related compounds
Other anionsMagnesium fluoride
Magnesium bromide
Magnesium chloride
Other cationsberyllium iodide
calcium iodide
strontium iodide
barium iodide
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references
 
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Magnesium iodide
Identifiers
CAS number10377-58-9 YesY,  (anhydrous)
75535-11-4 (hexahydrate)
7790-31-0 (octahydrate)
PubChem66322
ChemSpider59700 N
Jmol-3D imagesImage 1
Properties
Molecular formulaMgI2 (anhydrous)
MgI2.6H2O (hexahydrate)
MgI2.8H2O (octahydrate)[1]
Molar mass278.1139 g/mol (anhydrous)
386.2005 g/mol (hexahydrate)
422.236 g/mol (octahydrate)
Appearancewhite crystalline solid
Odorodorless
Density4.43 g/cm³ (anhydrous solid)
2.353 g/cm³ (hexahydrate solid)
2.098 g/cm³ (octahydrate solid)
Melting point637 °C (anhydrous, decomposes)
41 °C (octahydrate, decomposes)
Solubility in water54.7 g/100 cm³ (anhydrous, 0 °C)
148 g/100 cm³ (anhydrous, 18 °C)[2]
81 g/100 cm³ (octahydrate, 20 °C)
Solubilitysoluble in ether, alcohol and ammonia
Structure
Crystal structureHexagonal (anhydrous)
Monoclinic (hexahydrate)
Orthorhombic (octahydrate)
Hazards
R-phrasesR36 R38 R42 R43 R61
S-phrasesS22 S36/37/39 S45 S53[3]
NFPA 704
NFPA 704.svg
1
3
1
Related compounds
Other anionsMagnesium fluoride
Magnesium bromide
Magnesium chloride
Other cationsberyllium iodide
calcium iodide
strontium iodide
barium iodide
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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.

Reactions[edit]

Magnesium iodide can be prepared from magnesium oxide, magnesium hydroxide, and magnesium carbonate by treatment with hydroiodic acid:[4]

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.[5]

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

Usage of magnesium iodide in the Baylis-Hillman reaction tends to give (Z)-vinyl compounds.[6]

References[edit]

  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
  3. ^ Safety (MSDS) data for magnesium iodide
  4. ^ Patnaik, Pradyot (2003), Handbook of Inorganic Chemicals, McGraw-Hill Professional, pp. 527–528, ISBN 0-07-049439-8, retrieved 2007-12-09 
  5. ^ Wilsmore, N. T. M. (1891). "Note on Magnesium Iodide". In James Hector. Report of the Third Meeting of the Australasian Association for the Advancement of Science. Sydney: The Association. p. 116. Retrieved 2007-12-09. 
  6. ^ Tietze, Lutz-Friedjan; Brasche, Gordon; Gericke, Kersten (2006), Domino Reactions in Organic Synthesis, Wiley-VCH, p. 59, ISBN 3-527-29060-5, retrieved 2007-12-09