Aluminium borohydride

Aluminium borohydride[1]
IUPAC name

Aluminium borohydride
Other names

Aluminum borohydride, aluminium tetrahydroborate, aluminum tetrahydroborate
Identifiers
CAS number 16962-07-5 Y=
ChemSpider 55734 Y
Jmol-3D images Image 1
Properties
Molecular formula H12AlB3
Molar mass 71.51 g mol−1
Appearance colorless liquid
Melting point

-64.5 °C, 209 K, -84 °F
Boiling point

44.5 °C, 318 K, 112 °F
Solubility in water reacts
Hazards
Flash point Spontaneously ignites
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Aluminium borohydride, also known as aluminium tetrahydroborate, (in American English, aluminum borohydride and aluminum tetrahydroborate, respectively) is the chemical compound with the formula Al(BH4)3. It is a volatile pyrophoric liquid which is used as rocket fuel or jet fuel, or as a reducing agent in laboratories. Unlike most other metal–borohydrides, which are ionic structures, aluminium borohydride is a covalent compound.[2][3]

Contents

Preparation

Aluminium borohydride is formed by the reaction between sodium borohydride with aluminium chloride:[4]

3 NaBH4 + AlCl3 → Al(BH4)3 + 3 NaCl

or as the non-pyrophoric tetrahydrofuran (THF) adduct, by the analogous reaction of calcium borohydride and aluminium chloride in THF:[2]

3 Ca(BH4)2 + 2 AlCl3 → 3 CaCl2 + 2 Al(BH4)3

Reactions

Like all borohydrides, this compound is a reducing agent and hydride donor. It reacts with water to give elemental hydrogen gas,[4] and reduces carboxylic esters, aldehydes, and ketones to alcohols.[2]

References

  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, FL: CRC Press. pp. 4–39. ISBN 0-8493-0594-2. 
  2. ^ a b c J. Kollonitsch & O. Fuchs (1955). "Preparation of Aluminium Borohydride and its Applications in Organic Reductions". Nature 176 (4492): 1081. doi:10.1038/1761081a0. 
  3. ^ Miwa, K.; Ohba, N.; Towata, S.; Nakamori, Y.; Züttel, A.; Orimo, S. (2007). "First-principles study on thermodynamical stability of metal borohydrides: Aluminum borohydride Al(BH4)3". J. Alloys Compd. 446–447: 310–314. doi:10.1016/j.jallcom.2006.11.140. 
  4. ^ a b Perry, Dale L.; Phillips, Sidney L. (1995). Handbook of Inorganic Compounds. CRC Press. pp. 3–4. ISBN 0-8493-8671-3. http://books.google.com/?id=0fT4wfhF1AsC. Retrieved 2007-12-09. 

Further reading