1-Carboxyethyl-3-Methylimidazolium Hydrogensulfate stands out as a modern ionic liquid, a result of combining organic and inorganic chemistry in one versatile molecule. Its molecular formula is C8H14N2O5S, and it features an imidazolium cation, paired with a hydrogensulfate anion. As with many compounds in this family, the raw materials required for its synthesis come from methyimidazole and other controllable feedstocks, making production scalable for industrial, academic, and specialty chemical use.
You look at the structure and see an imidazole ring, methylated for extra stability, linked to a carboxyethyl tail. Against the cation, the hydrogensulfate anion delivers acidic properties. The molecule forms a tight ionic bond, and that ionic nature explains most of its unusual properties. It hits the bench as a solid at room temperature but melts easily, creating a clear or slightly yellow liquid. The compound can appear as powder, flakes, crystals, or even pearls, depending on the processing route and storage conditions. Chemical suppliers ship this material in solid or liquid forms; each has advantages based on handling and application purpose.
Being an ionic liquid, its density tops water: measured typically around 1.4-1.5 g/cm³. This means it’s heavy for its size and feels dense even as a powder or set of pearls. The melting point usually reads 80-100°C, but pure lots run slightly lower or higher based on trace impurities. You handle it in the lab much like you handle other ionic liquids, but there’s a key difference: its hydrogensulfate group loves water, soaking up moisture from the air, so containers should stay tightly sealed. Viscosity checks are important for researchers; high viscosity in pure form challenges anyone pipetting smaller amounts. Spectroscopic analysis (NMR, FTIR) makes it easy to verify purity—most chemists check for absence of residual solvents or unreacted imidazole rings.
For trade and customs purposes, the HS Code typically falls under 2921.29, covering quaternary ammonium salts and derivatives. This is important if you’re moving quantities across borders, since proper documentation impacts import taxes and regulatory scrutiny. Usage in research, catalysis, or material science means it’s not usually subject to narcotics or precursor regulations, but safe handling and accurate labelling form the backbone of logistics.
From first contact, the material shows acidity thanks to its hydrogensulfate group. It can corrode bare metals, and sometimes tingles the skin, a cue for gloves and goggles. Respiratory protection becomes more of a concern in powder form—fine dust can upset the upper airways, and repeated exposure may leave some irritation. Environmental health and safety protocols treat 1-Carboxyethyl-3-Methylimidazolium Hydrogensulfate as “potentially harmful if mishandled”, but most facilities rate it well below the typical hazards found with volatile organics or classic acids. Spilled liquid absorbs fast into surfaces and can stain if left too long; regular spill kits for mild acids work well. Disposal reading points to water dilution, seepage to neutralization chambers, and strong controls against accidental mixing with bases or bleach, where vigorous or unpredictable reactions could occur.
In material science, 1-Carboxyethyl-3-Methylimidazolium Hydrogensulfate gains respect as a green solvent, alternative acid catalyst, and ionic conduction enhancer. Electrochemists test it in fuel cells, energy storage, and proton exchange work, due to its stable ionic environment and moderate viscosity. Synthetic chemists deploy it in organic transformations, particularly acidic and coupling reactions that struggle in traditional solvents. The molecule’s liquid state at higher temperatures eliminates phase-transfer problems common with traditional salts, letting reactions run smoother and more efficiently.
As an insider, working with the substance day-to-day, it’s always about balancing reactivity with safety. Atom economy matters in research—ionic liquids like this one help cut solvent waste, so the green chemistry advocates push for adoption wherever possible. Limitations still exist: cost fluctuates with feedstock price, and purification after use isn’t trivial. After several runs, product quality may drop unless care is taken to remove decomposed acid fractions. For process engineers, solution often means closed-loop recycling, tight environmental controls, and monitoring for shifts in viscosity or color as warning signs. Analytical teams keep samples on standby for testing—UV-vis and NMR serving as go-to techniques for real-time checks.
Even as demand for green chemicals rises, discussions continue over the long-term safety of large-scale ionic liquid use. Clearly labelled raw materials, robust training for lab staff, and detailed emergency plans fill gaps in knowledge left by the literature. Manufacturers ramp up quality-control specs, offering traceability and third-party verification for critical properties like melting point and solution behavior. Researchers aim for higher purity, better shelf-life, and formulations that stay stable under field conditions, since moisture can still shift physical properties without warning. New packaging formats, such as pre-measured ampoules or liquid-filled cartridges, cut down on direct handling risks. Collaboration between industrial users and university labs often paves the way for protocols capable of meeting both safety targets and application needs, showing how this fascinating material can fit into a sustainable, forward-looking chemical toolbox.
