Aluminium borohydride

Aluminium borohydride[1]
Structural formula of the aluminium borohydride molecule
Names
IUPAC name
Aluminium borohydride
Other names
Aluminium borohydride, aluminium tetrahydroborate
Identifiers
3D model (JSmol)
ChemSpider
UNII
UN number 2870
  • InChI=1S/Al.3BH4/h;3*1H4/q+3;3*-1 checkY
    Key: LNJYEMMRSAGORU-UHFFFAOYSA-N checkY
  • InChI=1/Al.3BH4/h;3*1H4/q+3;3*-1
    Key: LNJYEMMRSAGORU-UHFFFAOYAC
  • [Al+3].[BH4-].[BH4-].[BH4-]
Properties
AlB3H12
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)
reacts
Hazards
Flash point Spontaneously ignites
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

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

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, Florida: 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. Bibcode:1955Natur.176.1081K. 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. arXiv:cond-mat/0610853. doi:10.1016/j.jallcom.2006.11.140. S2CID 97032806.
  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

  • 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.