1-Butyl-3-methylimidazolium tetrafluoroborate
[CAS# 174501-65-6]

Identification

• Classification: Chemical reagent >> Organic reagent >> Ionic liquid
• Name: 1-Butyl-3-methylimidazolium tetrafluoroborate
• Molecular Formula: C₈H₁₅N₂.BF₄
• Molecular Weight: 226.02
• CAS Registry Number: 174501-65-6
• EC Number: 638-831-1
• SMILES: [B-](F)(F)(F)F.CCCCN1C=C[N+](=C1)C

Properties

• Density: 1.2077
• Melting point: -71 °C
• Refractive index: 1.52
• Flash point: 288 °C

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS09 Danger
• Risk Statements: H301-H315-H319-H335-H411
• Safety Statements: P261-P264-P264+P265-P270-P271-P273-P280-P301+P316-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	3	H301
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Skin corrosion	Skin Corr.	1C	H314
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Serious eye damage	Eye Dam.	1	H318

Discovery and Applications

1-Butyl-3-methylimidazolium tetrafluoroborate (BMIM BF4) is a versatile ionic liquid with the molecular formula C8H15BF4N2. As a member of the imidazolyl ionic liquid family, BMIM BF4 has attracted great interest due to its unique properties and wide applications in various fields.

The development of BMIM BF4 is part of the extensive research on ionic liquids that began in the mid-20th century. Researchers were looking for alternatives to traditional organic solvents that could offer advantages such as low volatility, non-flammability, and high thermal stability. The synthesis of BMIM BF4 involves a direct reaction between 1-butyl-3-methylimidazolium chloride (BMIM Cl) and sodium tetrafluoroborate (NaBF4). In this process, BMIM Cl reacts with NaBF4 to produce BMIM BF4 and sodium chloride (NaCl) as a byproduct. The resulting BMIM BF4 is then purified to obtain a high-purity ionic liquid.

The most notable application of BMIM BF4 is as a green solvent. Traditional organic solvents are often volatile and toxic, posing risks to the environment and health. In contrast, BMIM BF4 is non-volatile and recyclable, making it an environmentally friendly alternative. It is widely used in organic synthesis to dissolve a wide range of compounds and promote cleaner, more efficient reactions. Its ability to stabilize transition states and intermediates makes it valuable in catalysis.

BMIM BF4 is highly regarded in electrochemical applications for its excellent ionic conductivity and electrochemical stability. It can be used as an electrolyte in batteries, fuel cells, and supercapacitors, helping to improve the efficiency and lifetime of these devices. Its wide electrochemical window and low viscosity make it ideal for the development of advanced energy storage and conversion systems.

In the field of catalysis, BMIM BF4 can be used as both a solvent and a co-catalyst. It can dissolve a wide range of catalytic species and promote homogeneous catalysis. Its role in improving reaction rates, selectivity, and yields makes it an essential component in a variety of catalytic processes, including hydrogenations, oxidations, and polymerizations.

BMIM BF4 is used in extraction and separation processes for its ability to selectively dissolve and separate different compounds. It is used in liquid-liquid extraction to extract valuable components from mixtures, such as bioactive compounds from plant materials or metals from ores. Its low volatility and recyclability enhance the sustainability of these processes.

In materials science, BMIM BF4 is used to synthesize and modify materials with specific properties. It plays a role in the preparation of nanoparticles, polymers and other advanced materials. BMIM BF4 can act as a template or stabilizer during the synthesis of nanomaterials, affecting their size, shape and stability. This application leads to the development of new materials tailored for various technological applications.

References

2004. Chloroperoxidase from Caldariomyces fumago is active in the presence of an ionic liquid as co-solvent. Biotechnology Letters, 26(24).
DOI: 10.1007/s10529-004-5087-6

2024. Process optimization and mechanism study of ionic liquid-based mixed amine biphasic solvents for CO2 capture in biogas upgrading procedure. Frontiers of Environmental Science & Engineering, 18(12).
DOI: 10.1007/s11783-024-1855-9

2009. Ionic liquid-promoted multi-component reaction: novel and efficient preparation of pyrazolo[3,4-b]pyridinone, pyrazolo[3,4-b]-quinolinone and their hybrids with pyrimidine nucleoside. Molecular Diversity, 13(3).
DOI: 10.1007/s11030-009-9168-2