1-Butyl-3-methylimidazolium hexafluorophosphate
[CAS# 174501-64-5]

Identification

• Classification: Chemical reagent >> Organic reagent >> Ionic liquid
• Name: 1-Butyl-3-methylimidazolium hexafluorophosphate
• Molecular Formula: C₈H₁₅N₂^.PF₆
• Molecular Weight: 284.18
• CAS Registry Number: 174501-64-5
• EC Number: 678-095-9
• SMILES: CCCCN1C=C[N+](=C1)C.F[P-](F)(F)(F)(F)F

Properties

• Density: 1.3727
• Melting point: 6.5 ºC
• Refractive index: 1.41

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	3	H336

Discovory and Applicatios

1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM PF6) is an ionic liquid known for its unique properties and diverse uses. With the molecular formula C8H15F6N2P, BMIM PF6 belongs to a class of organic salts that are liquid at room temperature and are used in a variety of industrial and scientific fields.

The discovery of BMIM PF6 was part of a broader exploration of ionic liquids, which attracted great interest in the mid-20th century. Researchers were looking for alternative solvents that could offer advantages over traditional organic solvents, such as low volatility, nonflammability, and high thermal stability. The synthesis of BMIM PF6 was derived from efforts to develop room temperature ionic liquids (RTILs) with desirable physicochemical properties for a range of applications.

BMIM PF6 is synthesized by the metathesis reaction of 1-butyl-3-methylimidazolium chloride (BMIM Cl) and hexafluorophosphates, such as potassium hexafluorophosphate (KPF6). In this process, BMIM Cl reacts with KPF6 to produce BMIM PF6 and potassium chloride (KCl) as a byproduct. The resulting BMIM PF6 is then purified to obtain high-purity ionic liquids suitable for a variety of applications.

The most prominent application of BMIM PF6 is as a green solvent in chemical processes. Traditional organic solvents are often harmful to the environment and health due to their volatility and toxicity. In contrast, BMIM PF6 is non-volatile and can be recycled, thereby reducing the environmental impact of chemical processes. It is used in organic synthesis, catalysis, and extraction processes where traditional solvents are less effective or more harmful.

BMIM PF6 is widely used in electrochemical applications due to its high ionic conductivity and electrochemical stability. It can be used as an electrolyte in batteries, fuel cells, and supercapacitors, helping to improve efficiency and performance. Its wide electrochemical window and low viscosity make it an excellent choice for these applications, helping to develop advanced energy storage and conversion devices.

In catalysis, BMIM PF6 can be used as both a solvent and a catalyst. Its ability to dissolve a wide range of organic and inorganic compounds makes it a versatile medium for catalytic reactions. BMIM PF6 is used in homogeneous and heterogeneous catalysis to promote reactions that are difficult to achieve with traditional solvents. Its use in catalysis can enable more efficient and selective processes, helping to develop sustainable chemical synthesis methods.

BMIM PF6 is used in various separation processes, including liquid-liquid extraction and gas absorption. Its unique properties enable it to selectively extract specific compounds from a mixture, thereby improving the efficiency and selectivity of separation processes. It is used in the purification of drugs, the extraction of metals, and the separation of organic compounds.

In materials science, BMIM PF6 is used to synthesize and modify materials with specific properties. It involves the preparation of nanoparticles, polymers, and other advanced materials. BMIM PF6 can act as a template or stabilizer in the synthesis of nanomaterials, affecting their size, shape, and stability. Its use in materials science has led to the development of new materials with properties tailored for various applications.

References

2000. Room-temperature ionic liquids as replacements for organic solvents in multiphase bioprocess operations. Biotechnology and Bioengineering, 69(2).
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2024. Eco-friendly solvents in liquid-liquid microextraction techniques for biological and environmental analysis: a critical review. Analytical and Bioanalytical Chemistry, 416(27).
DOI: 10.1007/s00216-024-05578-1

2024. Interfacial and mass transport phenomena in the tri-ethylene glycol-methane system at process conditions of natural gas dehydration. Journal of Petroleum Exploration and Production Technology, 14(12).
DOI: 10.1007/s13202-024-01868-7