Magnesium iodide

From Wikipedia, the free encyclopedia

Magnesium iodide
IUPAC name Magnesium iodide
Identifiers
CAS number [10377-58-9 (anhydrous)
75535-11-4 (hexahydrate)
7790-31-0 (octahydrate)]
Properties
Molecular formula MgI2 (anhydrous)
MgI2.6H2O (hexahydrate)
MgI2.8H2O (octahydrate)[1]
Molar mass 278.114 g/mol (anhydrous)
386.2005 g/mol (hexahydrate)
422.236 g/mol (octahydrate)
Appearance white crystalline solid
Density 4.43 g/cm³ (anhydrous solid)
2.353 g/cm³ (hexahydrate solid)
2.098 g/cm³ (octahydrate solid)
Melting point

637 °C (anhydrous, decomposes)
41 °C (octahydrate, decomposes)
Solubility in water 54.7 g/100 cm³ (anhydrous, 0 °C)
148 g/100 cm³ (anhydrous, 18 °C) [2]
81 g/100 cm³ (octahydrate, 20 °C)
Structure
Crystal structure Hexagonal (anhydrous)
Monoclinic (hexahydrate)
Orthorhombic (octahydrate)
Hazards
R-phrases R36 R38 R42 R43 R61
S-phrases S22 S36/37/39 S45 S53[3]
Related compounds
Other anions Magnesium fluoride
Magnesium bromide
Magnesium chloride
Other cations beryllium iodide
calcium iodide
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and 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.

[edit] Reactions

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].

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

 This inorganic compound-related article is a stub. You can help Wikipedia by expanding it.

[edit] References

  1. ^ Perry, Dale L. & Phillips, Sidney L., Handbook of Inorganic Compounds, CRC Press, pp. 240, ISBN 0849386713, <http://books.google.com/books?id=0fT4wfhF1AsC&pg=PA240&dq=%22magnesium+iodide%22&as_brr=3&ei=jDZcR--DA4fQiwGJ9MGwAw&ie=ISO-8859-1&sig=OczmUrZd3qb3uYKwOHfdAoOKqyA>. Retrieved on 2007-12-09 
  2. ^ Magnesium Iodide MSDS at AlfaAesar
  3. ^ Safety (MSDS) data for magnesium iodide
  4. ^ Patnaik, Pradyot, Handbook of Inorganic Chemicals, McGraw-Hill Professional, pp. 527-528, ISBN 0070494398, <http://books.google.com/books?id=Xqj-TTzkvTEC&pg=RA1-PA527&dq=%22magnesium+iodide%22&as_brr=3&ei=5DVcR4uFPKXQiQGOiemkAw&ie=ISO-8859-1&sig=QOvcMUABsG5Kn7NshePb2P0VMFg#PRA1-PA527,M1>. Retrieved on 2007-12-09 
  5. ^ Wilsmore, N. T. M. (1891). "Note on Magnesium Iodide". James Hector Report of the Third Meeting of the Australasian Association for the Advancement of Science: 116, Sydney: The Association. Retrieved on 2007-12-09. 
  6. ^ Tietze, Lutz-Friedjan; Brasche, Gordon & Gericke, Kersten, Domino Reactions in Organic Synthesis, Wiley-VCH, pp. 59, ISBN 3527290605, <http://books.google.com/books?id=qijhLyZ6SokC&pg=PA59&dq=%22magnesium+iodide%22+reactions&as_brr=3&ei=m0BcR4HgAYq-igGB5sH6Aw&ie=ISO-8859-1&sig=hKziWjoeftgwxNyZMTGY5508YZc#PPA59,M1>. Retrieved on 2007-12-09