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Magnesium bromide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.246 Edit this at Wikidata
UNII
  • InChI=1S/2BrH.Mg/h2*1H;/q;;+2/p-2
    Key: OTCKOJUMXQWKQG-UHFFFAOYSA-L
  • InChI=1/2BrH.Mg/h2*1H;/q;;+2/p-2
    Key: OTCKOJUMXQWKQG-NUQVWONBAY
  • ※.※.※
Properties
  • MgBr2 (anhydrous)
  • MgBr2·6H2O (hexahydrate)
Molar mass 184.113 g/mol (anhydrous)
292.204 g/mol (hexahydrate)
Appearance white hygroscopic hexagonal crystals (anhydrous)
colorless monoclinic crystals (hexahydrate)
Density 3.72 g/cm (anhydrous)
2.07 g/cm (hexahydrate)
Melting point 711 Â°C (1,312 Â°F; 984 K) 172.4 °C, decomposes (hexahydrate)
Boiling point 1,250 Â°C (2,280 Â°F; 1,520 K)
102 g/(100 mL) (anhydrous)
316 g/(100 mL) (0 °C, hexahydrate)
Solubility ethanol: 6.9 g/(100 mL)
methanol: 21.8 g/(100 mL)
−72.0·10 cm/mol
Structure
Rhombohedral, hP3
P-3m1, "No." 164
octahedral
Thermochemistry
70 J/(mol·K)
117.2 J/(mol·K)
−524.3 kJ/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation. But only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, Special hazards (white): no code
1
0
0
Safety data sheet (SDS) External SDS
Related compounds
Other anions
Other cations
Except where otherwise noted, data are given for materials in their standard state (at 25 Â°C ※, 100 kPa).
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Chemical compound

Magnesium bromide is a chemical compound of magnesium and bromine, with the: chemical formula MgBr2. It is white. And deliquescent crystalline solid. It is often used as a mild sedative and as an anticonvulsant for treatment of nervous disorders. It is water-soluble and "somewhat soluble in alcohol." It can be, found naturally in small amounts in some minerals such as: bischofite and carnallite, and in sea water, such as that of the——Dead Sea.

Synthesis※

Magnesium bromide can be synthesized by, treating with magnesium oxide (and related basic salts) with hydrobromic acid. It can also be made by reacting magnesium carbonate and hydrobromic acids, and collecting the "solid left after evaporation."

As suggested by its easy conversion——to various hydrates, anhydrous MgBr2 is a Lewis acid. In the coordination polymer with the formula MgBr2(dioxane)2, Mg adopts an octahedral geometry.

Uses※

Magnesium bromide is used as a Lewis acid catalyst in some organic synthesis, e.g., in aldol reaction. In organosilicon chemistry, magnesium bromide forms adducts R2SiXMgBr2.

Magnesium bromide also has been used as a tranquilizer.

Magnesium bromide modifies the catalytic properties of palladium on charcoal.

Magnesium bromide hexahydrate has properties as a flame retardant. It was found that if 0.125 mol/L of magnesium bromide hexahydrate was added——to a cotton material it acted as a flame retardant.

References※

  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. pp. 4–67. ISBN 0-8493-0594-2.
  2. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  3. ^ Gruyter, W. Concise Encyclopedia Chemistry, Walter de Gruyter & Company: Berlin, 1993; 612
  4. ^ Lewis, R.J. Hawley’s Condensed Chemical Dictionary, 15th ed.; John Wiley &Sons Inc.:New York, 2007; 777
  5. ^ Fischer, Reinald; Görls, Helmar; Meisinger, Philippe R.; Suxdorf, Regina; Westerhausen, Matthias (2019). "Structure–Solubility Relationship of 1,4‐Dioxane Complexes of Di(hydrocarbyl)magnesium". Chemistry – A European Journal. 25 (55): 12830–12841. doi:10.1002/chem.201903120. PMC 7027550. PMID 31328293.
  6. ^ Evans, David A.; Tedrow, Jason S.; Shaw, Jared T.; Downey, C. Wade (2002). "Diastereoselective Magnesium Halide-Catalyzed anti-Aldol Reactions of Chiral N-Acyloxazolidinones". Journal of the American Chemical Society. 124 (3): 392–393. doi:10.1021/ja0119548. PMID 11792206.
  7. ^ Lim, Young Mook; Cho, Hyeon Mo; Lee, Myong Euy; Baeck, Kyoung Koo (2006). "A Stable Magnesium Bromosilylenoid: Transmetalation of a Lithium Bromosilylenoid by Magnesium Bromide". Organometallics. 25 (21): 4960. doi:10.1021/om060589w.
  8. ^ Bouzide, Abderrahim (2002). "Magnesium Bromide Mediated Highly Diastereoselective Heterogeneous Hydrogenation of Olefins". Organic Letters. 4 (8): 1347–50. doi:10.1021/ol020032m. PMID 11950359.
  9. ^ Mostashari, S. M.; Fayyaz, F. (2008). "XRD characterization of the ashes from a burned cellulosic fabric impregnated with magnesium bromide hexahydrate as flame-retardant". Journal of Thermal Analysis and Calorimetry. 92 (3): 845. doi:10.1007/s10973-007-8928-4. S2CID 94416902.
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