1-Butyl-3-methyl-1H-imidazolium hydrogen sulfate
[CAS# 262297-13-2]

Identification

• Classification: Chemical reagent >> Organic reagent >> Ionic liquid
• Name: 1-Butyl-3-methyl-1H-imidazolium hydrogen sulfate
• Synonyms: 1-Butyl-3-methylimidazolium bisulfate; 1-Butyl-3-methylimidazolium hydrogen sulfate; 1-n-Butyl-3-methylimidazolium hydrogen sulfate
• Molecular Formula: C₈H₁₅N₂.HSO₄
• Molecular Weight: 236.29
• CAS Registry Number: 262297-13-2
• EC Number: 684-205-6
• SMILES: CCCCN1C=C[N+](=C1)C.OS(=O)(=O)[O-]

Properties

• Flash point: 284 °C

Safety Data

• Hazard Symbols: GHS05 Danger
• Risk Statements: H314
• Safety Statements: P260-P264-P280-P301+P330+P331-P302+P361+P354-P304+P340-P305+P354+P338-P316-P321-P363-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Serious eye damage	Eye Dam.	1	H318
Substances or mixtures corrosive to metals	Met. Corr.	1	H290

• Transport Information: UN 3265

Discovery and Applications

1-Butyl-3-methyl-1H-imidazole hydrogen sulfate (BMIM HSO₄) is an ionic liquid with the chemical formula C₈H₁₆N₂O₄S. The compound belongs to a class of substances with unique properties and wide applications in modern science and industry. 1-Butyl-3-methyl-1H-imidazole hydrogen sulfate was discovered in the early 21st century when ionic liquids were explored as potential environmentally friendly solvents and catalysts. Researchers aimed to develop ionic liquids that combined low volatility, high thermal stability and ionic conductivity with the ability to act as acidic catalysts. BMIM HSO₄ has a hydrogen sulfate anion, which is a promising candidate due to its strong acidity and good physical properties.

The synthesis of 1-butyl-3-methyl-1H-imidazolium hydrogen sulfate involves the following steps: 1-butyl-3-methylimidazolium cation is synthesized by reacting 1-methylimidazolium with butyl chloride, and the resulting 1-butyl-3-methylimidazolium chloride is then reacted with sulfuric acid to form 1-butyl-3-methylimidazolium hydrogen sulfate. This process produces a colorless to pale yellow liquid that is hygroscopic and has high thermal and chemical stability.

The main application of BMIM HSO₄ is catalysis. Its strong acidity makes it an effective catalyst for a variety of chemical reactions, including esterification, alkylation, and polymerization. The ionic liquid nature of BMIM HSO₄ enhances reaction rates and selectivity, making it a valuable tool in laboratory and industrial processes.

BMIM HSO₄ is widely used in green chemistry due to its environmentally friendly properties. As a solvent, it provides a non-volatile alternative to traditional organic solvents, reducing the release of harmful volatile organic compounds (VOCs) into the atmosphere. Its recyclability and reusability further promote sustainable chemical practices.

In analytical and industrial chemistry, BMIM HSO₄ is used for the extraction and separation of various compounds. Its ionic properties allow it to effectively dissolve a wide range of substances and can be used in processes such as liquid-liquid extraction and chromatography.

BMIM HSO₄ shows good promise in processing biomaterials to produce biofuels and biochemicals. Its strong acidity enables efficient decomposition of biomass components, thereby facilitating the conversion of renewable resources into valuable products.

In electrochemical applications, BMIM HSO₄ is used as an electrolyte in batteries and supercapacitors. Its high ionic conductivity and thermal stability improve the performance and lifetime of electrochemical devices.

References

2024. Recent chemical methods for metals recovery from printed circuit boards. Journal of Material Cycles and Waste Management, 26(4).
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2024. The evaluation of zinc and/or copper sulfuric acid leaching from brass ashes. Brazilian Journal of Chemical Engineering, 41(3).
DOI: 10.1007/s43153-024-00447-x

2024. Ionic liquid treated bacterial cellulose sheets as prospective biodegradable implant materials. Cellulose, 31(4).
DOI: 10.1007/s10570-024-05741-y