Aluminium borohydride

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Aluminium borohydride [1]
Aluminium-borohydride-2D-from-xtal.png
Names
IUPAC name
Aluminium borohydride
Other names
Aluminum borohydride, aluminium tetrahydroborate, aluminum tetrahydroborate
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
UNII
UN number 2870
  • InChI=1S/Al.3BH4/h;3*1H4/q+3;3*-1 Yes check.svgY
    Key: LNJYEMMRSAGORU-UHFFFAOYSA-N Yes check.svgY
  • 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
Appearancecolorless 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).
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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 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]

Related Research Articles

Silane is an inorganic compound with chemical formula, SiH4. It is a colourless, pyrophoric, toxic gas with a sharp, repulsive smell, somewhat similar to that of acetic acid. Silane is of practical interest as a precursor to elemental silicon. Silane with alkyl groups are effective water repellents for mineral surfaces such as concrete and masonry. Silanes with both organic and inorganic attachments are used as coupling agents.

Diborane Chemical compound

Diborane(6), generally known as diborane, is the chemical compound consisting of boron and hydrogen with the formula B2H6. It is a colorless, pyrophoric gas with a repulsively sweet odor. Synonyms include boroethane, boron hydride, and diboron hexahydride. Diborane is a key boron compound with a variety of applications. It has attracted wide attention for its electronic structure. Its derivatives are useful reagents.

Lithium aluminium hydride Chemical compound

Lithium aluminium hydride, commonly abbreviated to LAH, is an inorganic compound with the chemical formula LiAlH4. It is a grey solid, discovered by Finholt, Bond and Schlesinger in 1947. This compound is used as a reducing agent in organic synthesis, especially for the reduction of esters, carboxylic acids, and amides. The solid is dangerously reactive toward water, releasing gaseous hydrogen (H2). Some related derivatives have been discussed for hydrogen storage.

Zinc chloride Chemical compound

Zinc chloride is the name of chemical compounds with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. This white salt is hygroscopic and even deliquescent. Samples should therefore be protected from sources of moisture, including the water vapor present in ambient air. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

Cerium(III) chloride Chemical compound

Cerium(III) chloride (CeCl3), also known as cerous chloride or cerium trichloride, is a compound of cerium and chlorine. It is a white hygroscopic salt; it rapidly absorbs water on exposure to moist air to form a hydrate, which appears to be of variable composition, though the heptahydrate CeCl3·7H2O is known. It is highly soluble in water, and (when anhydrous) it is soluble in ethanol and acetone.

Sodium borohydride Chemical compound

Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula NaBH4. This white solid, usually encountered as a powder, is a reducing agent that finds application in chemistry, both in the laboratory and on an industrial scale. It has been tested as pretreatment for pulping of wood, but is too costly to be commercialized. The compound is soluble in alcohols, certain ethers, and water, although it slowly hydrolyzes.

Aluminium chloride Chemical compound

Aluminium chloride (AlCl3), also known as aluminium trichloride, describe compounds with the formula AlCl3(H2O)n (n = 0 or 6). They consist of aluminium and chlorine atoms in a 1:3 ratio, and one form also contains six waters of hydration. Both are white solids, but samples are often contaminated with iron(III) chloride, giving a yellow color.

McMurry reaction

The McMurry reaction is an organic reaction in which two ketone or aldehyde groups are coupled to form an alkene using a titanium chloride compound such as titanium(III) chloride and a reducing agent. The reaction is named after its co-discoverer, John E. McMurry. The McMurry reaction originally involved the use of a mixture TiCl3 and LiAlH4, which produces the active reagents. Related species have been developed involving the combination of TiCl3 or TiCl4 with various other reducing agents, including potassium, zinc, and magnesium. This reaction is related to the Pinacol coupling reaction which also proceeds by reductive coupling of carbonyl compounds.

Uranium borohydride Chemical compound

Uranium borohydride is the inorganic compound with the empirical formula U(BH4)4. Two polymeric forms are known, as well as a monomeric derivative that exists in the gas phase. Because the polymers convert to the gaseous form at mild temperatures, uranium borohydride once attracted much attention. It is solid green.

Titanium(III) chloride is the inorganic compound with the formula TiCl3. At least four distinct species have this formula; additionally hydrated derivatives are known. TiCl3 is one of the most common halides of titanium and is an important catalyst for the manufacture of polyolefins.

Borohydride

Borohydride refers to the anion [BH4], which is also called tetrahydroborate, and its salts. Borohydride or hydroborate is also the term used for compounds containing [BH4-nXn], where n is an integer from 0 to 3, for example cyanoborohydride or cyanotrihydroborate [BH3(CN)] and triethylborohydride or triethylhydroborate [BH(CH2CH3)3]. Borohydrides find wide use as reducing agents in organic synthesis. The most important borohydrides are lithium borohydride and sodium borohydride, but other salts are well known. Tetrahydroborates are also of academic and industrial interest in inorganic chemistry.

Aluminium hydride Chemical compound

Aluminium hydride (also known as alane or alumane) is an inorganic compound with the formula AlH3. It presents as a white solid and may be tinted grey with decreasing particle size and impurity levels. Depending upon synthesis conditions, the surface of the alane may be passivated with a thin layer of aluminum oxide and/or hydroxide. Alane and its derivatives are used as reducing agents in organic synthesis.

The reduction of nitro compounds are chemical reactions of wide interest in organic chemistry. The conversion can be effected by many reagents. The nitro group was one of the first functional groups to be reduced. Alkyl and aryl nitro compounds behave differently. Most useful is the reduction of aryl nitro compounds.

Sodium aluminium hydride Chemical compound

Sodium aluminium hydride or sodium alanate is an inorganic compound with the chemical formula NaAlH4. It is a white pyrophoric solid that dissolves in tetrahydrofuran (THF), but not in diethyl ether or hydrocarbons. It has been evaluated as an agent for the reversible storage of hydrogen and it is used as a reagent for the chemical synthesis of organic compounds. Similar to lithium aluminium hydride, it is a salt consisting of separated sodium cations and tetrahedral AlH
4
anions.

Niobium(IV) chloride Chemical compound

Niobium(IV) chloride, also known as niobium tetrachloride, is the chemical compound of formula NbCl4. This compound exists as dark violet crystals, is highly sensitive to air and moisture, and disproportiates into niobium(III) chloride and niobium(V) chloride when heated.

Diethylaluminium chloride Chemical compound

Diethylaluminium chloride, abbreviated DEAC, is an organoaluminium compound. Although usually given the chemical formula (C2H5)2AlCl, it exists as a dimer, [(C2H5)2AlCl]2 It is a precursor to Ziegler-Natta catalysts employed for the production of polyolefins. The compound is also a Lewis acid, useful in organic synthesis. The compound is a colorless waxy solid, but is usually handled as a solution in hydrocarbon solvents. It is highly reactive, even pyrophoric.

Zirconium(III) chloride Chemical compound

Zirconium(III) chloride is an inorganic compound with formula ZrCl3. It is a blue-black solid that is highly sensitive to air.

Carbonyl reduction

In organic chemistry, carbonyl reduction is the organic reduction of any carbonyl group by a reducing agent.

Nickel boride is the common name of materials composed chiefly of the elements nickel and boron that are widely used as catalysts in organic chemistry. Their approximate chemical composition is Ni2.5B, and they are often incorrectly denoted "Ni
2
B
" in organic chemistry publications.

In chemistry, aluminium(I) refers to monovalent aluminium in both ionic and covalent bonds. Along with aluminium(II), it is an extremely unstable form of aluminium.

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. 1 2 3 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. 1 2 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