Scientists began exploring quaternary phosphonium salts around the mid-20th century when organophosphorus chemistry picked up steam. Teams in Europe and North America pushed the boundaries of phase-transfer catalysis, and Tetrabutylphosphonium Bromide (TBPB) grew out of this push. The compound arrived in laboratory literature as researchers realized the value of phosphonium salts as strong bases and efficient phase transfer agents. TBPB became a key part of this class due to its favorable combination of solubility and reactivity, especially as the synthetic world started moving toward greener solvents and ionic liquids. Through the years, TBPB’s accessibility improved with advances in organophosphorus synthesis, making it a mainstay for organic chemists focused on catalysis and extraction.
Tetrabutylphosphonium Bromide stands out among quaternary phosphonium salts. The molecule features a central phosphorus atom bonded to four butyl groups, balancing with a bromide ion. These butyl chains make TBPB highly lipophilic, meaning it dissolves well in organic media. Market offerings often place TBPB in the spotlight for its versatility, from catalysis to electrochemistry. Companies supply it as a white crystalline solid, ready for use across chemical and industrial applications. Supply chains remain robust, with stock preparations available from both specialty and bulk distributors.
TBPB typically shows up as a white or off-white powder. Its molar mass clocks in at 348.38 g/mol. With a melting point hovering around 100°C, it holds up through rigorous lab procedures. Water solubility is present but not high, reflecting its stronger affinity for non-polar systems. Density usually lands near 1.1–1.2 g/cm³ for the solid form. Chemically, TBPB functions both as a source of bromide and a bulky phosphonium base. The molecule resists oxidation at room temperature, a boon for long-term storage. In my own work, I've found it often gives stable results, handling routine lab bench conditions without unexpected volatility or degradation.
Manufacturers label bottles of TBPB with product codes, batch numbers, and purity levels—often 98% or higher. Labels highlight storage guidance, such as keeping the product dry and avoiding strong oxidizers, acids, and sources of moisture. Shipping guidelines generally require well-sealed containers, sometimes double-bagged, to avoid water uptake or caking. Safety labeling includes pictograms for irritant and harmful chemicals, reinforcing the point that, despite its regular use, TBPB needs thoughtful handling. Each shipment comes with a Certificate of Analysis (CoA), so users can verify batch-to-batch consistency. Analytical data sometimes include HPLC or NMR verification of structure and purity.
Labs usually prepare TBPB by quaternizing tributylphosphine with butyl bromide. The reaction runs in a solvent such as acetonitrile or dichloromethane, often with gentle heating. The resulting salt precipitates as the reaction moves forward, and technologists isolate it by filtration. Product may undergo recrystallization from alcohol or acetone to bump up purity. Process optimization keeps the reaction efficient—timing, temperature, and solvent choice have an outsized effect on yield and cleanliness. Synthesis on a commercial scale often employs continuous flow reactors to maintain throughput and quality. The chemical equation stays simple by design: exploiting nucleophilic phosphine attack on the alkyl halide and driving to completion with controlled equivalents.
TBPB doesn’t just sit around as a passive salt. Its role as a phase-transfer catalyst makes it a player in a host of substitution and elimination reactions. In aqueous-organic systems, TBPB pulls anions across phase boundaries, speeding up slow reactions. TBPB’s phosphonium center provides a strong but non-nucleophilic base, suitable for deprotonation and alkylation of active methylene compounds. Chemists sometimes tailor TBPB further by swapping the bromide ion for other anions (through metathesis reactions), turning it into a precursor for other ionic liquids. In my experience, swapping out halides gives different solubility and thermal properties, expanding the range for electrochemistry and green solvent development. In reduction and coupling reactions, TBPB steers selectivity by managing ionic environments and stabilizing intermediates.
Search for TBPB and a slew of synonyms pop up: Tributylbutylphosphonium Bromide, N-Butyltributylphosphonium Bromide, and QPBr. Industry catalogs might list Phosphonium, tetrabutyl-, bromide (1:1) or buck TBPB for short. This diversity in naming sometimes bottles up procurement efforts, especially where catalog translations and regulatory lists differ, so checking the CAS number (3115-68-2) clears up confusion. In the field, chemists stick with TBPB or Tetrabutylphosphonium Bromide to keep communication straightforward. Knowing product synonyms streamlines both research and supply-chain logistics, shaving time off project timelines.
Working with TBPB, safety comes down to minimizing inhalation and direct contact. Gloves, goggles, and lab coats make the basics. Fume hoods control airborne particles, especially during weighing or transfer. TBPB can irritate skin and eyes. Ingestion and inhalation should be avoided. Manufacturers run comprehensive toxicological screening: Material Safety Data Sheets (MSDS) box up details about storage, firefighting measures, accidental release response, and disposal. Scientists dispose of TBPB waste according to local hazardous material codes. Emergency protocols—in case of spills or exposure—usually advise rinsing with water and seeking medical attention for lingering effects. Containers should stay tightly closed and moisture-free, stored in cool, ventilated spaces. These day-to-day best practices keep labs running smoothly without unnecessary interruptions.
TBPB punches above its weight in phase-transfer catalysis, where it helps shuttle ions across otherwise stubborn phase boundaries. I’ve used it to coax sluggish nucleophilic substitutions into high-gear, especially for making ethers, esters, and pharmaceuticals. Battery engineers look to TBPB and related phosphonium salts as electrolytes, leveraging thermal stability and conductivity. Polymer makers pick TBPB for ionomer synthesis and cross-linking reactions, seeking its unique ionic character. In extraction and purification, TBPB facilitates separations that regular salts can’t handle. Gas capture and separation engineers run experiments with TBPB-based ionic liquids to trap CO2 and SO2 under mild conditions, addressing challenges of clean energy and climate technology. Catalysts based on TBPB support experiments in sustainable chemical synthesis, cutting down on waste and hazardous solvents. The pharmaceutical industry and fine chemical synthesis especially value TBPB where tight reaction control matters.
Ongoing research pushes TBPB into new territory, highlighting its adaptability and persistent utility. I often see new publications probing how substituent changes on phosphonium salts affect reactivity, thermal stability, and toxicity—a crucial edge in sustainability drives. TBPB-based ionic liquids attract attention for green chemistry, since they sidestep volatile organic solvents. Scientists also dissect the mechanistic roles of TBPB in transition-metal catalysis, where the basicity and steric profile tweak reaction outcomes in subtle ways. Lab teams across academia and the commercial sector compete to hybridize TBPB with other cations or anions, hunting for custom ionic liquids tuned to battery, separation, and analytical needs. While the field brims with interest in new applications, detailed thermodynamic and kinetic characterizations stand out as the key to broader adoption. Each new patent and article brings fresh ideas, nudging TBPB into applications spanning from renewable energy to advanced materials.
Toxicity research on TBPB traces the delicate balance between effectiveness and safety. Animal studies flag moderate acute oral and dermal toxicity, with symptoms including respiratory distress and skin irritation at higher concentrations. Long-term carcinogenicity and mutagenicity results remain limited, but safety reviews suggest using protective gear in workplace settings. Biodegradability data indicate slow breakdown in aquatic environments, leading to caution flags in disposal and wastewater treatment. Chronic exposure implications might be unclear, so handling protocols stay conservative—better safe than sorry. Worker training programs stress careful storage and disposal; accidental exposure can mean skin rash, eye irritation, or gastrointestinal issues. Investment in new toxicity screens (such as in-vitro cellular models) keeps moving forward so regulators and consumers get clear risk profiles for TBPB-containing materials in the environment and workplace.
The outlook for TBPB grows brighter as researchers fold it into the search for smart materials, cleaner energy, and eco-friendly processes. Engineers working on solid-state batteries explore TBPB as a building block for non-flammable electrolytes, promising advances in power storage and safety. Chemists look to pair TBPB with novel anions to custom-tailor ionic liquids with properties for carbon capture, catalysis, and separation. With interest in green chemistry ramping up, TBPB’s thermal stability, low volatility, and robust catalytic skills tick the right boxes for replacing outdated, hazardous chemicals. Market growth rides on advances in sustainable manufacturing and fine chemical production, where process engineers fine-tune TBPB-based systems for lower cost, lower waste, and higher output. Regulatory agencies seek more robust environmental data, promising future work in toxicity reduction and lifecycle analysis. As more fields recognize that cleaner, safer chemistry isn’t a luxury but a necessity, TBPB finds itself at the edge of tomorrow’s breakthroughs, bringing practical, reliable results every step of the way.
Tetrabutylphosphonium bromide doesn’t exactly win awards for a catchy name. Still, this compound plugs into some important work. A lot of the heavy lifting happens out of sight, deep inside labs and factories. People don’t run across it at the grocery store, but a fair chunk of daily life traces back to chemical assistants just like this one.
A big talent here lies in helping chemical reactions run smoother and safer. In my years working alongside research teams, I saw how simple salt-like chemicals can become key supporting actors. Tetrabutylphosphonium bromide acts as what chemists call a phase transfer catalyst. Basically, this means it helps substances mix and react, even if they normally refuse to blend because one likes oil and the other likes water. Many medicines, plastics, and cleaning agents wouldn't get off the ground without somebody bridging that stubborn gap.
This doesn’t stop at just mixing problems. Process engineers often run into pollution or slow production if their reactions drag on for hours or spew unwanted byproducts. Add the right catalyst, and suddenly reactions speed up and yield more of the good stuff, not the junk. If a manufacturer pulls off the same job with less waste and cheaper inputs, the planet breathes a bit easier and costs stay in check.
Tetrabutylphosphonium bromide pops up in several roles beyond the phase transfer sweet spot. Electrochemists use it as an electrolyte in batteries and experimental cells. These electrolytes carry charges back and forth, which opens the door to new types of batteries or green chemistry tricks. Some companies chase after better solar fuel cells or more stable supercapacitors, and they test out all kinds of supporting materials, including this one.
The compound has also made itself useful in crystallography labs. Scientists studying the shapes and structures of proteins and molecules sometimes use this salt to coax crystals into forming—critical for unlocking new drugs and therapies.
No conversation about specialty chemicals lands right without looking at health and environmental risks. From what I’ve seen and read, tetrabutylphosphonium bromide doesn’t top any major hazard lists, but it still calls for careful handling. Gloves, goggles, and good ventilation stay standard. Engineers look for ways to keep it out of waterways, since bromide-containing chemicals can disrupt aquatic life at high concentration.
As the world pushes for safer chemical building blocks, researchers keep hunting for alternatives that balance performance, cost, and safety. Some promising projects look at ways to recycle used catalyst back into the system instead of tossing it after each batch.
So much of today's world rests on quiet breakthroughs. Compounds like tetrabutylphosphonium bromide show up more often behind the scenes than in headlines, yet they quietly connect bold innovation to real-world needs. Progress unfolds from this type of team player: useful in the right hands, always asking for a bit of respect and careful attention.
Tetrabutylphosphonium bromide carries the chemical formula C16H36BrP. Digging into this formula, you can see four butyl groups attached to a central phosphorous atom, finished with a bromide ion. Scientists and engineers don’t bother memorizing names like this for kicks—this compound brings real use in labs and industry, especially in the field of ionic liquids and organic synthesis.
Many folks think chemistry sits far from daily life, but accuracy in chemical formulas prevents real disasters. With C16H36BrP, each letter and number represents atoms locked in one specific arrangement. Getting the formula wrong could wreck a chemical reaction, leading to safety hazards or financial loss. Having worked side by side with colleagues in manufacturing, I’ve seen the consequences of arithmetic slip-ups or label confusion—wrong materials, lost investments, and even dangerous spills.
Phosphonium salts like this one have positively charged phosphorous centers surrounded by organic groups, matched with an anion such as bromide. They serve as phase transfer catalysts, shuttling ions between water and oil phases. This interaction makes them valuable for speeding up some reactions in pharma and chemical manufacturing. Pharmaceutical labs have moved fast to greener chemistry, and ionic liquids using salts like tetrabutylphosphonium bromide have played a part there. The formula isn’t just classroom trivia—it means tens of thousands of tons of less harmful solvents dumped into the environment each year.
From my own time in wet labs, sometimes the hardest part came in tracking down impurities. As soon as someone switched out tetrabutylphosphonium bromide for a similar salt by mistake, the whole mixture changed: the solubility shifted, crystals vanished, yields tanked. Anyone who’s stayed after hours to salvage a batch knows the sting of small errors. Understanding the correct structure—C16H36BrP—determines how the compound will react, what conditions it needs, and how safely it can be handled.
Tetrabutylphosphonium bromide’s role extends to electrochemistry and advanced materials as well. Every atom in the formula counts: the long hydrocarbon chains grant unique properties like low melting points or high conductivity. This supports developments in batteries and plasticizers. When industry teams tested new plastic blends, they depended on formulas like C16H36BrP to achieve desired flexibility and long-term stability. The foundation starts with that chemical identity.
Education programs across the world keep stressing fundamentals because accuracy keeps people safe and operations running. Seasoned chemists can recall the embarrassment (and expense) of a mislabeled bottle. Modern software and inventory tools cut these problems, but every expert still checks the basics before starting work. Tetrabutylphosphonium bromide, with its specific formula C16H36BrP, highlights why solid core knowledge stays essential in both research circles and factory floors.
Reducing risks and promoting innovation stands on a base of clear, shared knowledge. Companies should provide thorough training, transparent labeling, and instant access to data sheets. Investing in high-quality sourcing, consistent supply chains, and lab information management systems protects workers and end users alike. Each time teams treat the formula seriously, they add another layer of safety and quality to the final product, building trust and success for everyone involved.
Tetrabutylphosphonium bromide shows up in many chemical labs, usually as a phase transfer catalyst. Some researchers appreciate how it dissolves well in both water and organic solvents, allowing reactions to move along faster. But convenience and function can end up coming with trade-offs—understanding the real-world risks matters as much as performance.
For anyone handling tetrabutylphosphonium bromide, safety data sheets remain the gold standard. Those documents often warn of irritation to eyes and skin. No surprise, since a lot of quaternary phosphonium salts will cause burning or redness on direct contact. Inhalation exposure can lead to irritation in the respiratory tract, especially if the powder gets airborne during weighing or mixing.
Long hours in the lab taught me that it only takes one quick, sloppy glove change to feel the sting of a chemical where you don’t want it. Always having emergency eye wash stations nearby can limit the outcome if things go sideways. Wearing gloves made from nitrile or neoprene, not just latex, lowers risk. Research led by toxicologists usually shows that tetrabutylphosphonium bromide doesn’t cause major chronic problems at the sorts of concentrations used in a lab, but you don’t want to cut corners.
A major concern for these kinds of chemicals comes after use—what ends up in the drain may not just sit around harmlessly. Some phosphonium compounds stick around in water, and bacteria can have a tough time breaking them down. That can mean a risk for aquatic life. According to published environmental science studies from groups at places like the University of Cambridge and environmental agencies in the EU, low levels can still affect fish and some aquatic invertebrates. Phosphonium salts have a way of binding to proteins in the gills, upsetting balance, and affecting survival.
Safe handling always comes down to training and respect for the risks, no matter what chemical you have. The evidence suggests that tetrabutylphosphonium bromide does not belong in the high-hazard group, but ignoring standard protocols turns small risks into bigger ones. Eye protection, lab coats, and working under a fume hood don’t just help the person doing the work—the habits set an example for everyone in the room. I’ve seen senior researchers nip bad safety habits in the bud by enforcing rules, not by cutting slack because “nothing’s ever happened so far.”
Using less-toxic alternatives when possible makes sense. Some labs have switched to greener catalysts or ionic liquids that degrade more easily. Storing and disposing of tetrabutylphosphonium bromide waste in sealed, labeled containers lowers the chance of spills and keeps it from entering the water supply. Chemical suppliers and universities now include disposal guidelines as standard in their safety briefings, helping researchers play their part.
Education, accountability, and substitution—these factors keep labs safer and the environment cleaner. Every person working with chemicals should get familiar with the risks, check the latest research, and look for ways to improve their practices over time.
Tetrabutylphosphonium bromide doesn’t look intimidating at a glance. Most folks would call it a routine chemical, but anyone who’s spent time around labs knows appearances don’t tell the whole story. The truth: this salt brings fire and health risks you can’t ignore. Years around chemicals taught me respect often keeps you out of trouble—for both you and the next person in line. So keeping this compound in check starts with understanding its flammability, its ability to irritate skin, and its sensitivity to air and moisture. Mistakes made once can spill into the work of others down the line.
Plastic bottles with tight seals work best for storage. Tetrabutylphosphonium bromide handles air poorly, especially in humid spaces, so using a glass or high-density polyethylene bottle with a screw cap keeps it dry. I’ve seen cheap containers crumble with time; replacing damaged bottles means less hassle later. Labels must state the chemical name, concentration, date received, and expiry date—no half-measures, no scribbled shorthand. A clear, bold marker prevents confusion or accidental misuse, and helps anyone spot deteriorating stocks that need discarding.
Few people think about sunlight, but even chemicals in dark bottles don’t always escape light degradation. The compound belongs in a cool, ventilated storage cabinet, out of direct sunlight. Temperatures just above freezing slow degradation, yet never store it below freezing. I learned the hard way: freezing can crack containers or change the salt’s consistency, making it lumpy or difficult to measure. Humidity leads to caking and clumping, so dry cabinets stand as a must.
Basic rules save lives. A lockable chemical cabinet cuts down on unauthorized access. Only trained staff should handle this material; reading the safety data sheet never counts as wasted time. Working in a fume hood makes a difference, protecting folks from dust that causes nose and throat irritation. Having gloves, safety goggles, and a sturdy lab coat isn’t about ticking boxes—it stops accidents that can scar or ruin working days.
Waste builds up in busy labs. Large volumes or contaminated stock should move straight into collection for hazardous materials—not down the drain. Any spills demand fast action using dry absorbent materials. Wet cleanups only exaggerate hazards, spreading contamination. I always keep spill kits on hand, along with clear instructions for staff and students. The cost of a single spill often outweighs a year’s worth of proper storage.
Tetrabutylphosphonium bromide isn’t the scariest substance in the storeroom, but careless handling adds up over time. Small slip-ups—an unlabeled bottle, a misplaced cap, a cluttered shelf—create problems that compound. Smart storage habits, earned through hard lessons, make a safer, smoother lab for everyone picking up the next pipette or flask. Taking shortcuts for convenience usually invites much bigger problems later. Store smart, work safer.
Purity shows up as a non-negotiable factor in chemical research. In my lab experience, even a tiny impurity can blow an entire day’s work. Most bottles of tetrabutylphosphonium bromide I’ve used hit a purity level upwards of 98%, usually stated right on the label. Big suppliers like Sigma-Aldrich, Thermo Fisher, and Alfa Aesar take this seriously because a single percent off can sabotage a reaction’s consistency, especially in catalysis, phase-transfer, or advanced organic synthesis. A lower purity brings in risks—unexpected by-products or, worse, misleading data that takes hours or weeks to untangle. I’ve seen it happen: one bad batch sent an entire project group into troubleshooting mode for a month.
With this compound, water or alcohols can sneak in because the substance pulls moisture from humid air. That’s why folks store it in a tightly capped container, usually in a dry area with desiccants nearby. Purity also influences safety. Unwanted residues can introduce hazards, toxic by-products, or odd smells. Phosphonium salts sometimes pick up a light amine scent when less pure; top-grade material stays nearly odor-free.
Tetrabutylphosphonium bromide stands out on the shelf as a white or faintly off-white powder. At room temperature, it won’t flow like table salt. It feels a bit clumpy, almost like damp flour, due to its hygroscopic nature. Freshly opened, high-purity product usually shows a clean, bright white tone. Over time, if left exposed, it may turn slightly yellow as it draws in moisture or interacts with light. I’ve watched a batch sit out during an afternoon seminar and come back to find the edges turning sticky and discolored.
No crystalline glimmer comes from this compound. Anyone expecting flakes or sparkles like sodium chloride will be surprised. You get a dense pile—no distinct grains, just solid mass and a tendency to stick to the scoop or spatula. This texture makes accurate weighing tricky at times. Static or residual moisture builds up, and clumps stick to the plastic or glassware. Good practice, learned the hard way, means weighing quickly and capping containers right away. In hot or damp rooms, these problems multiply.
If the batch looks yellow, brown, or noticeably wet, it’s usually a sign of problems. Sometimes, the material contains traces of phosphorus impurities, which hints at rough handling or improper synthesis. Discoloration warrants testing before using the batch for anything critical.
High purity and proper appearance go beyond clean lab notebooks. In synthetic chemistry or making ionic liquids, even amateurs see yield changes if the quality isn’t spot on. Ionic liquids get popular in research for their unique properties, but only if the starting materials hold up to scrutiny. Poor quality progenitors build poor results—garbage in, garbage out.
To dodge headaches, chemists rely on reputable suppliers and insist on rigorous quality checks before use. Labs often run quick NMR, IR, or elemental analysis to double-check what’s in the container. If there’s ever a question about purity, running a small test reaction saves time and stress down the line. In my own projects, a habit of checking before trusting cuts down on wasted effort and builds better, more reliable science.
| Names | |
| Preferred IUPAC name | tributyl(butyl)phosphanium bromide |
| Other names |
TBPB
Tetrabutylphosphoranylium bromide Tetra-n-butylphosphonium bromide |
| Pronunciation | /ˌtɛtrə.bjuːˌtaɪl.fɒsˈfoʊni.əm ˈbroʊmaɪd/ |
| Identifiers | |
| CAS Number | 3115-68-2 |
| Beilstein Reference | 1716829 |
| ChEBI | CHEBI:63953 |
| ChEMBL | CHEMBL429762 |
| ChemSpider | 50347 |
| DrugBank | DB11164 |
| ECHA InfoCard | ECHA InfoCard: 100.142.513 |
| EC Number | 608-170-8 |
| Gmelin Reference | 81877 |
| KEGG | C19229 |
| MeSH | D017978 |
| PubChem CID | 109106 |
| RTECS number | EW3465000 |
| UNII | Q6H311B58K |
| UN number | Not regulated |
| CompTox Dashboard (EPA) | DTXSID9020707 |
| Properties | |
| Chemical formula | C16H36BrP |
| Molar mass | 322.36 g/mol |
| Appearance | White to off-white crystalline powder |
| Odor | Odorless |
| Density | 1.10 g/cm³ |
| Solubility in water | soluble |
| log P | 0.4 |
| Vapor pressure | Negligible |
| Acidity (pKa) | 28.8 (DMSO) |
| Basicity (pKb) | pKb ≈ 4.5 |
| Magnetic susceptibility (χ) | -76.0×10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.485 |
| Viscosity | 119 cP (25 °C) |
| Dipole moment | 1.12 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 341.6 J·mol⁻¹·K⁻¹ |
| Hazards | |
| Main hazards | Harmful if swallowed or if inhaled. Causes skin irritation. Causes serious eye irritation. |
| GHS labelling | GHS07, GHS09 |
| Pictograms | GHS05,GHS07 |
| Signal word | Warning |
| Hazard statements | H302, H315, H319, H335 |
| Precautionary statements | P264, P270, P273, P301+P312, P330, P501 |
| NFPA 704 (fire diamond) | NFPA 704: 1-1-0 |
| Lethal dose or concentration | LD50 Oral - rat - 595 mg/kg |
| LD50 (median dose) | LD50 (median dose): >2000 mg/kg (rat, oral) |
| NIOSH | TT6300000 |
| PEL (Permissible) | Not established |
| REL (Recommended) | No REL established |
| Related compounds | |
| Related compounds |
Tetrabutylphosphonium chloride
Tetrabutylphosphonium iodide Tetrabutylphosphonium hydroxide Tetrabutylphosphonium fluoride Tetrabutylammonium bromide |
