Tetrabutylammonium bromide
[CAS# 1643-19-2]

Identification

• Classification: Chemical reagent >> Organic reagent >> Amine salt (ammonium salt)
• Name: Tetrabutylammonium bromide
• Synonyms: Tetrabutyl ammonium bromide; TBAB
• Molecular Formula: C₁₆H₃₆BrN
• Molecular Weight: 322.37
• CAS Registry Number: 1643-19-2
• EC Number: 216-699-2
• SMILES: CCCC[N+](CCCC)(CCCC)CCCC.[Br-]

Properties

• Density: 1.15 g/mL
• Melting point: 103 °C
• Boiling point: 144.3 °C (734 mmHg)
• Flash point: 100 °C
• Water solubility: 600 g/L (20 °C)

Safety Data

• Hazard Symbols: GHS07;GHS08;GHS09 Warning
• Risk Statements: H302-H315-H319-H335-H361-H411-H412
• Safety Statements: P203-P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P318-P319-P321-P330-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Reproductive toxicity	Repr.	2	H361
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Reproductive toxicity	Repr.	2	H361fd
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

Tetrabutylammonium bromide is a quaternary ammonium salt commonly used in organic synthesis and various chemical processes. It is a versatile compound that has found widespread applications in both industrial and academic research. Its discovery stems from the need for phase transfer catalysts and ionic compounds that could facilitate reactions in both aqueous and non-aqueous environments.

Tetrabutylammonium bromide plays a key role as a phase transfer catalyst. It enables the transfer of ionic species from one phase (typically aqueous) to another (usually organic) by acting as a carrier of ions across the immiscible boundary. This property makes it highly useful in organic chemistry, particularly in reactions such as nucleophilic substitutions, alkylations, and other processes that involve ionized species. The compound's ability to improve reaction rates and yields has led to its adoption in both laboratory and industrial settings.

In addition to its role as a catalyst, Tetrabutylammonium bromide is widely used as an electrolyte in electrochemical processes. It provides the necessary ionic conductivity in various systems, particularly in the development of batteries, capacitors, and electroplating processes. Its stability and solubility in organic solvents make it a preferred choice in many electrochemical applications. Moreover, it is utilized in the preparation of ionic liquids, which are of significant interest for their potential in green chemistry and advanced materials science.

The structure of Tetrabutylammonium bromide features a large tetrahedral ammonium ion with four butyl groups, which increases its solubility in organic solvents. This solubility, combined with its ionic nature, makes it ideal for applications that require a strong, soluble ionic compound. It is also employed in chromatography and other analytical techniques to assist in the separation of compounds based on their ionic properties.

Tetrabutylammonium bromide has become a vital component in many areas of chemical research and industry due to its functionality as a phase transfer catalyst, electrolyte, and ionic medium. As interest in ionic liquids and electrochemical applications continues to grow, its utility is likely to expand further in the coming years.

References

2020. Dissolution and deacetylation of chitin in ionic liquid tetrabutylammonium hydroxide and its cascade reaction in enzyme treatment for chitin recycling. Carbohydrate Polymers, 231, 115605.
DOI: 10.1016/j.carbpol.2019.115605

2015. Stereoelectronic effects: a simple yet powerful tool to manipulate anion affinity. Organic & Biomolecular Chemistry, 13(7), 1930-1935.
DOI: 10.1039/c4ob02470b

2013. Synthesis of 2-Nitroglycals from Glycals Using the Tetrabutylammonium Nitrate-Trifluoroacetic Anhydride-Triethylamine Reagent System and Base-Catalyzed Ferrier Rearrangement of Acetylated 2-Nitroglycals. The Journal of Organic Chemistry, 78(17), 8742-8752.
DOI: 10.1021/jo401165y