Tetrabutylammonium Bromide: A Deep-Dive into Physical Characteristics and Core Uses

What is Tetrabutylammonium Bromide?

Tetrabutylammonium Bromide stands out in the world of ammonium salts for both its versatility and reliability in laboratory and industrial settings. Its chemical formula is C₁₆H₃₆BrN, and this fairly simple structure speaks to a unique balance between organic and inorganic chemistries, owing to its tetraalkyl substitution and halide ion. The product draws from a long line of alkylammonium compounds, each valued for making phase transfer catalysts, ions for chemical analysis, or key ingredients in materials science. In a classroom, someone holding these flakes, crystals, or powdered solids notices no strong odor, and the texture feels waxy between the fingers—a far cry from old-school salts. This material rarely forms a classic solution in water without agitation but shows stubborn persistence in many organic solvents, making it crucial in synthetic work.

Main Properties and Structure

Those who have spent time in the lab recognize its appearance immediately: colorless to white crystalline powder, sometimes pressed into pinhead pearls or larger flakes to ease weighing. With a molecular weight of 322.37 g/mol and a density measuring close to 1.04 g/cm³, it packs some mass but rarely clumps, avoiding hassle during transfer. Its melting point hovers between 101–103 °C, so it can stay solid at standard storage temperatures. Tetrabutylammonium Bromide absorbs moisture but does not cake or corrode, a welcome trait in the bottled chemicals shelf. One might store it in glass or high-density polyethylene containers, out of direct sunlight, away from strong acids.

Specifications, HS Code, and Formula

Manufacturers and traders tag this chemical under HS Code 2923900000, listed among other quaternary ammonium compounds. Documentation typically references a purity of 98% or above, low halide impurities, minimal water content, and consistent crystallinity. Analytical labs use these details to ensure reactions proceed with no surprises. The chemical formula becomes a shorthand: C₁₆H₃₆BrN, a description every chemist will recognize, and one that comes up on every delivery docket and hazard assessment sheet. I have seen much frustration when formulas are not visible or confirmed, leading to a scramble in daily work—clear labelling and transparent reporting matter a lot.

Density, Physical Forms, and Storage Insights

Tetrabutylammonium Bromide’s density, at around 1.04 g/cm³, means it feels substantial but not heavy like lead or iron salts. Its solid state allows for easy dosing—those white flakes or crystalline chunks don’t produce fine dust easily, so inhalation risk is low, an important safety consideration. In some facilities, it appears in powder or pearl form, both easy to scoop and weigh, with minimal clumping when kept dry. I have prepared titrations where moisture in the weighing room changed the powder’s handling; using desiccators and climate-controlled cabinets, I always look to keep containers shut tight. This precaution keeps the product uniform and avoids subtle changes that could disrupt reactions or material synthesis.

Chemical Safety, Hazards, and Handling

Tetrabutylammonium Bromide rarely ranks as highly hazardous, but this doesn’t mean it can be handled with disregard. The solid may cause irritation if dust enters eyes or lands on sensitive skin. Workers wear gloves, safety glasses, and lab coats as a daily ritual, both habit and requirement. In enclosed or poorly ventilated rooms, exposure isn’t likely to elevate risks sharply, but no one takes that chance, and safety data sheets back up the cautious routines. No one in my experience has suffered more than mild irritation, but constant vigilance—especially during weighing, mixing, or dissolving—isn’t overkill. It pays to know that its decomposition releases toxic gases, which underscores the need for good fume extraction when heating it or mixing in strong acids.

Raw Materials and Manufacturing Insights

Sourcing reliable Tetrabutylammonium Bromide starts with top-quality butylamine, bromoalkanes, and pure ammonia solutions—each step in the synthetic route can bring distinct byproducts. Producers keep these raw materials strictly segregated, and batch reports show they actively monitor bromide content, secondary amines, and water load. The best batches arrive crystal clear, with no yellowing or residue in the bottle, an assurance of stability and minimal harmful contaminants. Suppliers who cut corners quickly hear back from chemical buyers—the downstream impact can jam reactors or contaminate entire chemical runs. Quality certifications, often following ISO, add credibility.

Applications Across Chemistry and Industry

Tetrabutylammonium Bromide finds its way into dozens of applications in organic synthesis. Phase transfer catalysis is a key use—by straddling oil and water phases, the compound helps ions move and react, speeding up processes that would otherwise be sluggish or impossible. Analytical chemists trust it as a supporting electrolyte for non-aqueous electrochemistry. Battery developers toy with its use in research on next-generation power cells, giving rise to new hopes for cleaner tech. In my own work, I’ve seen it in both academic benchwork and scale-up processes, often as a key intermediate in the preparation of other quaternary salts, a real workhorse behind the scenes.

Solubility, Usage Formats, and Material Considerations

Handling Tetrabutylammonium Bromide presents choices, shaped by process and equipment. In some operations, dissolving the solid directly into solvents yields a clear liquid; in others, a suspension works better. The compound dissolves well in polar organics—methanol, ethanol, acetonitrile—but less so in non-polar media. These choices affect how quickly reactions go, how easily mixtures get filtered, and even the purity of the end result. Some industries receive shipments in bulk containers of flakes, some in single-use sachets of powdered material, each format tailored to storage space, shelf life, and purity needs. Over time, storage experience teaches what shelf conditions matter: dry air, moderate temperature, tight seals, and regular reviews to watch for caking or odd odor.

Environmental and Hazardous Considerations

Disposing of Tetrabutylammonium Bromide takes planning—wastewater shouldn’t carry significant loads into sewer systems, as the bromide ion and organic backbone might persist. Responsible labs and industrial plants collect solid waste for hazardous disposal, often incinerating or using specialized landfills for chemicals. The environmental rules around quaternary ammonium compounds grow stricter every year. Stewardship falls not just to compliance teams, but to every technician who tips even a gram into the bin. Reading past environmental impact reports makes a point: legacy pollution comes from many small slips over time, not just headline spills. So, all in all, best practice keeps even minor waste streams under lock and key, with every drum and bottle marked for tracking.

Looking Ahead: Safe Use and Sustainable Sourcing

Chemists, technicians, and purchasing managers can improve sustainability by seeking out greener production pathways. Recent years have seen a spike in interest around minimizing hazardous reagents in the synthetic process of Tetrabutylammonium Bromide. Some producers now publicize greener routes, lower-emission energy sources, or closed-loop recycling schemes for solvents and byproducts. Down the line, stricter labeling, expanded safety data sheets, and staff training pay off with fewer incidents and cleaner processes. My own routines changed after one scare—a mislabeled drum taught the hard lesson about double-checking supplier paperwork and training every new hand. Attention, not automation, brings safe outcomes.