Tetrabutylammonium bromide (TBAB) is a
quaternary ammonium salt
In chemistry, quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure , R being an alkyl group or an aryl group. Unlike the ammonium ion () and the primary, secondary, or tertiary ammonium cations ...
with a
bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...
commonly used as a
phase transfer catalyst
In chemistry, a phase-transfer catalyst or PTC is a catalyst that facilitates the transition of a reactant from one phase into another phase where reaction occurs. Phase-transfer catalysis is a special form of heterogeneous catalysis. Ionic reac ...
. It is used to prepare many other
tetrabutylammonium
Tetrabutylammonium is a quaternary ammonium cation with the formula (C4H9)4sup>+. It is used in the research laboratory to prepare lipophilic salts of inorganic anions. Relative to tetraethylammonium derivatives, tetrabutylammonium salts are more ...
salts by
salt metathesis
A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding a ...
reactions. The anhydrous form is a white solid.
In addition to being cheap, tetrabutylammonium bromide is also environmentally friendly, has a greater degree of selectivity, is operationally simple, non-corrosive, and can be recycled easily as well.
Preparation and reactions
Tetrabutylammonium bromide can be prepared by the alkylation of
tributylamine
Tributylamine (TBA) is an organic compound with the molecular formula (C4H9)3N. It is a colorless liquid with an amine-like odor.
Uses
Tributylamine is used as a catalyst (proton acceptor) and as a solvent in organic syntheses and polymerization ...
with
1-bromobutane.
Tetrabutylammonium bromide is used to prepare other salts of the tetrabutylammonium cation by
salt metathesis reaction
A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding a ...
s.
[, , ;.]
It serves as a source of
bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...
ions for substitution reactions. It is one of a commonly-used
phase transfer catalyst
In chemistry, a phase-transfer catalyst or PTC is a catalyst that facilitates the transition of a reactant from one phase into another phase where reaction occurs. Phase-transfer catalysis is a special form of heterogeneous catalysis. Ionic reac ...
. As its melting point is just over 100 °C and decreases in the presence of other reagents, it can be considered an
ionic liquid
An ionic liquid (IL) is a salt in the liquid state. In some contexts, the term has been restricted to salts whose melting point is below a specific temperature, such as . While ordinary liquids such as water and gasoline are predominantly made of ...
.
Role in semi-clathrate formation
TBAB is being extensively studied as a thermodynamic promoter in the formation of semi-clathrate hydrates which greatly brings down the pressure - temperature requirement for forming gas hydrates.
See also
*
Tetrabutylammonium tribromide
Tetrabutylammonium tribromide, abbreviated to TBATB, is a pale orange solid with the formula (C4H9)4r3. It is a salt of the lipophilic tetrabutylammonium cation and the linear tribromide anion. The salt is sometimes used as a reagent used in or ...
, with an additional Br
2 unit
*
Tetrabutylammonium fluoride
Tetra-''n''-butylammonium fluoride, commonly abbreviated to TBAF and ''n''-Bu4NF, is a quaternary ammonium salt with the chemical formula (CH3CH2CH2CH2)4N+F−. It is commercially available as the white solid trihydrate and as a solution in tetra ...
*
Tetrabutylammonium chloride
Tetrabutylammonium chloride is the organic compound with the formula (C4H9)4NCl. A white water-soluble solid, it is a quaternary ammonium salt of chloride. It is a precursor to other tetrabutylammonium salts. Often tetrabutylammonium bromide
...
*
Tetrabutylammonium iodide
Tetrabutylammonium is a quaternary ammonium cation with the formula (C4H9)4sup>+. It is used in the research laboratory to prepare lipophilic salts of inorganic anions. Relative to tetraethylammonium derivatives, tetrabutylammonium salts are mor ...
References
{{organic-compound-stub
Tetrabutylammonium salts