Magnesium iodide
- 10377-58-9 (anhydrous) checkY
- 75535-11-4 (hexahydrate) ☒N
- 7790-31-0 (octahydrate) checkY
- 59700 ☒N
- 233-825-1
- W74QE3H320 (anhydrous) checkY
- 72I5H6SWMT (octahydrate) checkY
- InChI=1S/2HI.Mg/h2*1H;/q;;+2/p-2 ☒NKey: BLQJIBCZHWBKSL-UHFFFAOYSA-L ☒N
- InChI=1/2HI.Mg/h2*1H;/q;;+2/p-2Key: BLQJIBCZHWBKSL-NUQVWONBAV
- I[Mg]I
- [Mg+2].[I-].[I-]
- MgI2 (anhydrous)
- MgI2·6H2O (hexahydrate)
- MgI2·8H2O (octahydrate)[1]
- 278.1139 g/mol (anhydrous)
- 386.2005 g/mol (hexahydrate)
- 422.236 g/mol (octahydrate)
- 4.43 g/cm3 (anhydrous solid)
- 2.353 g/cm3 (hexahydrate solid)
- 2.098 g/cm3 (octahydrate solid)
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)
- Hexagonal (anhydrous)
- Monoclinic (hexahydrate)
- Orthorhombic (octahydrate)
entropy (S⦵298)
formation (ΔfH⦵298)
- Health 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gas
- Flammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oil
- Instability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calcium
- Special hazard COR: Corrosive; strong acid or base. E.g. sulfuric acid, potassium hydroxide
Magnesium iodide is an inorganic compound with the chemical formula Mg I 2. It forms various hydrates MgI2·xH2O. Magnesium iodide is a salt of magnesium and hydrogen iodide. These salts are typical ionic halides, being highly soluble in water.
Uses
[edit ]Magnesium iodide has few commercial uses, but can be used to prepare compounds for organic synthesis.
Preparation
[edit ]Magnesium iodide can be prepared from magnesium oxide, magnesium hydroxide, and magnesium carbonate by treatment with hydroiodic acid:[3]
Reactions
[edit ]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]
Demethylation of certain aromatic methyl ethers can be afforded using magnesium iodide in diethyl ether.[6]
Hydrates
[edit ]Two hydrates are known, the octahydrate and the nonahydrate, both verified by X-ray crystallography These hydrates feature [Mg(H2O)6]2+ ions.[7]
References
[edit ]- ^ Perry, Dale L.; Phillips, Sidney L. (1995), Handbook of Inorganic Compounds, CRC Press, p. 240, ISBN 0-8493-8671-3 , retrieved 2007年12月09日
- ^ Magnesium Iodide MSDS at AlfaAesar [permanent dead link ]
- ^ Patnaik, Pradyot (2003), Handbook of Inorganic Chemicals, McGraw-Hill Professional, pp. 527–528, ISBN 0-07-049439-8 , retrieved 2007年12月09日
- ^ 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年12月09日.
- ^ Tietze, Lutz-Friedjan; Brasche, Gordon; Gericke, Kersten (2006), "Domino Reactions in Organic Synthesis", Chemical Reviews, 96 (1), Wiley-VCH: 115–136, doi:10.1021/cr950027e, ISBN 3-527-29060-5, PMID 11848746 , retrieved 2007年12月09日
- ^ Yamaguchi, Seiji; Nedachi, Masahiro; Yokoyama, Hajime; Hirai, Yoshiro (October 1999). "Regioselective demethylation of 2,6-dimethoxybenzaldehydes with magnesium iodide etherate". Tetrahedron Letters. 40 (41): 7363–7365. doi:10.1016/S0040-4039(99)01411-2.
- ^ Hennings, Erik; Schmidt, Horst; Voigt, Wolfgang (2013). "Crystal Structures of Hydrates of Simple Inorganic Salts. I. Water-Rich Magnesium Halide Hydrates MgCl2·8H2O, MgCl2·12H2O, MgBr2·6H2O, MgBr2·9H2O, MgI2·8H2O and MgI2·9H2O". Acta Crystallographica Section C Crystal Structure Communications. 69 (11): 1292–1300. doi:10.1107/S0108270113028138. PMID 24192174.