Tetraethylammonium tetrafluoroborate
[CAS# 429-06-1]

Identification

• Classification: Chemical reagent >> Organic reagent >> Amine salt (ammonium salt)
• Name: Tetraethylammonium tetrafluoroborate
• Molecular Formula: C₈H₂₀N^.BF₄
• Molecular Weight: 217.06
• CAS Registry Number: 429-06-1
• EC Number: 207-055-1
• SMILES: [B-](F)(F)(F)F.CC[N+](CC)(CC)CC

Properties

• Melting point: 370-380 ºC (Expl.)

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Hazard Statements: H302-H312-H315-H319-H332-H335-H410
• Precautionary Statements: P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P317-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
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H312
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1C	H314

Discovory and Applicatios

Tetraethylammonium tetrafluoroborate is a quaternary ammonium salt with the chemical formula C8H20BF4N. It consists of a tetraethylammonium cation (C8H20N+) paired with a tetrafluoroborate anion (BF4−). The compound is a white crystalline solid and is often used in various applications in both organic and inorganic chemistry due to its distinctive properties.

The discovery and synthesis of tetraethylammonium tetrafluoroborate were part of the broader exploration of quaternary ammonium salts, which are well-known for their ability to dissolve both organic and inorganic materials and for their usefulness in a variety of chemical reactions. The tetrafluoroborate anion, BF4−, is an effective counterion in many applications, particularly in ionic liquids and electrochemical processes, due to its high stability and weakly coordinating nature.

Tetraethylammonium tetrafluoroborate has significant applications in electrochemistry. It is often used as an electrolyte in non-aqueous electrolytic solutions and batteries, particularly in lithium-ion batteries and supercapacitors. The stability of the BF4− anion, combined with the good solubility of the tetraethylammonium cation in organic solvents, makes it suitable for use in these high-performance electrochemical systems. The compound's ionic conductivity and electrochemical stability at high voltages are crucial for its role in energy storage and conversion technologies.

In addition to its applications in electrochemistry, tetraethylammonium tetrafluoroborate is also used in organic synthesis, where it serves as a source of the tetrafluoroborate anion. The tetrafluoroborate anion is often used to replace other anions in organic reactions, as it is relatively inert and can stabilize reactive intermediates. Tetraethylammonium tetrafluoroborate has been employed in the synthesis of various organic compounds, including those involving nucleophilic substitution reactions and ionic liquid synthesis.

Another application of tetraethylammonium tetrafluoroborate is in the field of ionic liquids. Ionic liquids are salts that remain in the liquid state at or near room temperature, and tetraethylammonium tetrafluoroborate has been explored as a component of these solvents. The compound's ionic nature and low viscosity make it useful in the development of ionic liquids for use in a wide range of chemical processes, such as catalysis, extraction, and separation. Ionic liquids like tetraethylammonium tetrafluoroborate are especially useful in applications that require environmentally friendly, non-volatile solvents.

The compound is also employed in catalysis, where its role as a phase transfer catalyst is utilized. Tetraethylammonium tetrafluoroborate can help facilitate reactions between two immiscible phases by transferring a reactive species from one phase to another, typically from an aqueous to an organic phase. This ability to enhance the rate of chemical reactions is valuable in many synthetic processes, including those in the pharmaceutical and fine chemical industries.

Tetraethylammonium tetrafluoroborate is relatively stable under normal conditions but should be handled with care. As with many salts, it is important to avoid contact with moisture, as it may cause the compound to decompose or form unwanted byproducts. The compound is typically stored in dry conditions and handled using standard safety procedures for chemicals.

In conclusion, tetraethylammonium tetrafluoroborate is an important compound with a variety of applications, including in electrochemistry, organic synthesis, ionic liquids, and catalysis. Its stability, conductivity, and ability to form ionic liquids make it a valuable reagent and solvent in both industrial and laboratory settings. The continued study and use of tetraethylammonium tetrafluoroborate reflect its importance in modern chemical and material science.

References

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DOI: 10.1039/c0ee00337a10.1039/c0ee00337a

2010 Structure and dynamics of electrical double layers in organic electrolytes. Phys. Chem. Chem. Phys., 12, 5468.
DOI: 10.1039/c000451k

2010 Graphene-based materials in electrochemistry. Chem. Soc. Rev., 39, 3157.
DOI: 10.1039/b923596e