1-Butyl-3-methylimidazolium hydrogen sulfate belongs to the expanding family of ionic liquids, defined by their ionic bonds, low volatility, and remarkable stability. Often used in both research and industrial contexts, this compound serves as an alternative to traditional organic solvents. The molecular formula for 1-butyl-3-methylimidazolium hydrogen sulfate is C8H16N2O4S. Its chemical structure features an imidazolium cation paired with the hydrogen sulfate anion, creating a salt that remains a liquid at or near room temperature. In practice, you’ll encounter it in several physical forms, but many labs and chemical suppliers provide it in a clear, viscous liquid state, with occasional batches appearing as slightly yellow liquids or even crystalline masses depending on levels of moisture absorption and purity.
Pouring 1-butyl-3-methylimidazolium hydrogen sulfate from its original bottle, you might recognize its high viscosity, distinct from traditional organic solvents. Its density comes in at around 1.21 to 1.23 g/cm³ at 20°C. At room temperature, the substance typically appears as a colorless to pale yellow liquid, though fluctuations in temperature and humidity can cause partial crystallization or the appearance of flakes. Its melting point sits near -8°C, so under most storage and operating conditions, it causes fewer issues with solidification compared to other ionic liquids. As with other imidazolium-based salts, it has low vapor pressure, so it doesn’t evaporate into the workspace air, reducing inhalation risk. In large-scale applications, you occasionally find a stable powder or pearl form designed for dosing efficiency, underscoring the flexibility for different production environments.
The cation, 1-butyl-3-methylimidazolium, features a five-membered imidazole ring substituted at the nitrogen with one methyl and one butyl group. Attached to the nitrogen atom, the butyl group confers hydrophobic character, impacting the solubility profile of the compound. The hydrogen sulfate anion (HSO4-) brings acidic properties and facilitates broad utility, especially in catalysis and extraction processes. The molecular weight rests at about 236.29 g/mol. Chemically, it acts as a strong ion-pair donor, resulting in unique properties such as high ionic conductivity and nonflammability. For logistics, the HS Code most commonly used for shipments is 3824999999, which reflects its classification as an organic compound in international trading systems. Batch specifications from reliable suppliers emphasize purity levels above 99%, drying loss below 0.5%, and controlled chloride content to maintain stability during sensitive procedures.
Opening a sample or shipment of 1-butyl-3-methylimidazolium hydrogen sulfate, you see why density matters in chemical processing: it determines storage requirements, influences solubility for reactants, and affects movement within reactors. Around 1.21 to 1.23 g/cm³ gives a definite weight in hand and means the material won’t float or disperse easily in lower density solvents, which must be considered for separation processes. Liquid remains the dominant delivery mode, though certain producers offer solid crystals, semi-solid flakes, or even fine powders for specialized handling. Under controlled cooling, the liquid solidifies smoothly, retaining its pale color and transparency that turns slightly opaque in the presence of minor impurities or moisture. In solution, it remains clear and colorless, ensuring no interference with optical detection methods.
It pays to understand the safety and environmental profile of every chemical in the lab or plant. 1-Butyl-3-methylimidazolium hydrogen sulfate, despite its lower volatility, still requires careful use. Skin or eye contact causes irritation, so handlers rely on goggles and gloves. Though nonflammable, accidental spills demand prompt cleaning, as the substance can absorb water and degrade in performance. Inhalation concerns recede thanks to low vapor pressure, offering some reassurance compared to volatile solvents like acetone or toluene. Most suppliers mark it as a harmful substance for aquatic life due to its ionic content, urging against direct release into drains or waterways. Waste management falls under local chemical disposal regulations. Material safety data sheets recommend storage in air-tight containers, at stable room temperatures, and away from incompatible chemicals such as strong bases and oxidizing agents. No one wants a reactive scenario in the workroom.
No industrial chemist ignores the benefits of ionic liquids for catalysis, separation, and synthesis. 1-Butyl-3-methylimidazolium hydrogen sulfate often works as a raw input for processes demanding strong acidity alongside high stability. Synthesis of fine chemicals, pharmaceuticals, and specialty polymers see its use. The liquid’s ionic nature means it dissolves a broad spectrum of organic molecules and inorganic salts, supporting extraction operations and green chemistry goals. Because it persists with little decomposition up to nearly 200°C, its lifecycle outlasts most organic solvents in recyclability and reuse. Equipment corrosion decreases, yields improve, and side-reactions drop—yet the push for less hazardous substitutes underscores constant vigilance. Biodegradation testing and environmental risk analysis show it persists longer than conventional solvents, yet ongoing research into bio-based alternatives reflects a growing sense of corporate responsibility. Still, for now, the search for a more stable, less hazardous acidic medium keeps this ionic liquid in steady demand.
