Aluminium borohydride

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Aluminium borohydride[1]
Structural formula of the aluminium borohydride molecule
CAS number 16962-07-5 N=
ChemSpider 55734 YesY
Jmol-3D images Image 1
Molecular formula H12AlB3
Molar mass 71.51 g mol−1
Appearance colorless liquid
Melting point −64.5 °C (−84.1 °F; 208.7 K)
Boiling point 44.5 °C (112.1 °F; 317.6 K)
Solubility in water reacts
Flash point Spontaneously ignites
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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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, and as a reducing agent in laboratories. Unlike most other metal–borohydrides, which are ionic structures, aluminium borohydride is a covalent compound.[2][3]


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


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]


  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. Retrieved 2007-12-09. 

Further reading[edit]

  • Fletcher, Edward; Foster, Hampton; Straight, David (1959). "Aluminum Borohydride and Mixtures with Hydrocarbons in Jet Engine Combustor Ignition". Industrial & Engineering Chemistry 51 (11): 1389. doi:10.1021/ie50599a044. 
  • Hinkamp, James B.; Hnizda, Vincent (1955). "Aluminum Borohydride Preparation". Industrial & Engineering Chemistry 47 (8): 1560. doi:10.1021/ie50548a032.