Tetrabutylammonium bromide

Chemical properties

white crystals or powder

The Uses of Tetrabutylammonium bromide

Tetrabutylammonium Bromide is used in the synthesis of polymer solar cells. Also used in the synthesis of single component green-light emitting electrochemical cells.

Definition

ChEBI: Tetrabutylammonium bromide is a tetrabutylammonium salt with bromide as the anionic counterpart. It is an organic bromide salt and a tetrabutylammonium salt.

Benefits

Tetrabutylammonium bromide is an environmentally benign, non-volatile, non-flammable, non-corrosive, low-cost, commercially available ammonium salt with high thermal and chemical stability. In TBAB, tetrabutylammonium salt can dissolve in both aqueous as well as in organic solvents, which helps to transport the water-soluble anionic reactants into the organic phase. Moreover, molten TBAB was also employed as an efficient ionic liquid to carry out organic transformations under solvent-free conditions[1].

General Description

Tetrabutylammonium bromide, a quaternary ammonium compound widely used as a phase transfer catalyst. TBAB decreases the retention time and removes peak tailing by acting as an ion pair reagent during the chromatographic analysis of quaternary ammonium compounds. In the molten state, TBAB behaves like an ionic liquid, which is a promising green alternative to organic solvents in polymer synthesis.

Flammability and Explosibility

Not classified

Properties

Tetrabutylammonium bromide is a commonly used phase transfer catalyst. As its melting point is just over 100 °C and decreases in the presence of other reagents, it can be considered an ionic liquid.

Preparation

Tetrabutylammonium bromide can be prepared by the alkylation of tributylamine with 1-bromobutane.

Purification Methods

Crystallise the salt from *benzene (5mL/g) at 80o by adding hot n-hexane (three volumes) and allowing to cool. Dry it over P2O5 or Mg(ClO4)2, under vacuum. The salt is very hygroscopic. It can also be crystallised from ethyl acetate or dry acetone by adding diethyl ether and dried in vacuo at 60o for 2 days. It has been crystallised from acetone by addition of diethyl ether. It is so hygroscopic that all manipulations should be carried out in a dry-box. It has been purified by precipitation from a saturated solution in dry CCl4 on addition of cyclohexane or by recrystallisation from ethyl acetate, then heating in vacuum to 75o in the presence of P2O5. [Symons et al. J Chem Soc, Faraday Trans 1 76 2251 1908.] It also recrystallises from CH2Cl2/diethyl ether and is dried in a vacuum desiccator over P2O5. [Blau & Espenson J Am Chem Soc 108 1962 1986, Beilstein 4 IV 657.]

References

[1] Banik B, et al. Tetrabutylammonium Bromide (TBAB) Catalyzed Synthesis of Bioactive Heterocycles. Molecules, 2020; 25: 5918.