1-Butyl-3-methylimidazolium thiocyanate
[CAS# 344790-87-0]

Identification

• Classification: Chemical reagent >> Organic reagent >> Ionic liquid
• Name: 1-Butyl-3-methylimidazolium thiocyanate
• Molecular Formula: C₉H₁₅N₃S
• Molecular Weight: 197.30
• CAS Registry Number: 344790-87-0
• EC Number: 682-764-0
• SMILES: CCCCN1C=C[N+](=C1)C.C(#N)[S-]

Properties

• Flash point: 206.5 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H312-H332-H412
• Safety Statements: P261-P264-P270-P271-P273-P280-P301+P317-P302+P352-P304+P340-P317-P321-P330-P362+P364-P501

Hazard Classification

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

• Transport Information: UN 2810

Discovery and Applications

1-Butyl-3-methylimidazolium thiocyanate (BMIM SCN) is a room temperature ionic liquid (RTIL) that has attracted much attention due to its unique properties and wide range of applications. As an imidazolyl ionic liquid, BMIM SCN combines the advantages of its cationic and anionic components to exhibit excellent thermal stability, low volatility, and high ionic conductivity.

The discovery of BMIM SCN can be traced back to the growing interest in ionic liquids in the late 20th century. Researchers explored various combinations of cations and anions to develop new RTILs with tailored properties. Imidazolium-based ionic liquids, such as BMIM SCN, are particularly promising due to their versatility and stability. The synthesis and characterization of BMIM SCN is part of this broad effort to create functional ionic liquids for a variety of applications.

The synthesis of 1-Butyl-3-methylimidazolium thiocyanate involves a simple ion exchange reaction. It generally follows the following steps: The synthesis begins by reacting 1-methylimidazole with a butyl halide (bromide or chloride) to form 1-butyl-3-methylimidazolium bromide (BMIM Br) or chloride (BMIM Cl). The BMIM halide is then reacted with an excess of potassium thiocyanate (KSCN) or sodium thiocyanate (NaSCN) to replace the halide ions with thiocyanate ions, thereby obtaining BMIM SCN. The resulting BMIM SCN is purified by washing and drying to remove any remaining impurities.

BMIM SCN is widely used as a solvent in organic synthesis and catalysis. It is able to dissolve a wide range of compounds, including polar and non-polar substances, making it a versatile medium for various chemical reactions. It has been used in the synthesis of pharmaceuticals, fine chemicals, and polymers, and its properties can enhance reaction rates and selectivity.

In electrochemistry, BMIM SCN is an effective electrolyte due to its high ionic conductivity and stability. It is used in the development of batteries, supercapacitors, and electrochemical sensors. Its low volatility and thermal stability make it suitable for high temperature and long-duration applications, thereby improving the performance and lifetime of electrochemical devices.

As an ionic liquid, BMIM SCN contributes to green chemistry initiatives by providing an environmentally friendly alternative to traditional organic solvents. Its non-flammability and low vapor pressure reduce the risk of air pollution and harmful emissions. Researchers are exploring its use in a variety of sustainable processes, including biomass conversion and carbon dioxide capture.

BMIM SCN is used in separation processes such as liquid-liquid extraction and gas absorption. Its unique solvation properties allow for efficient separation of complex mixtures, including extraction of metal ions and organic compounds. It is particularly useful in pharmaceutical purification and treatment of industrial waste streams.

In materials science, BMIM SCN is used in the synthesis and processing of advanced materials. It serves as a template or medium for the preparation of nanoparticles, nanocomposites, and conducting polymers. Its role in controlling the morphology and properties of these materials is critical for applications in electronics, catalysis, and sensor technologies.

References

2015. Ionic Liquids in Catalysis. Chemical Reviews, 115(14).
DOI: 10.1021/cr500013