Tetrabutylphosphonium chloride (abbreviated as TBPC, CAS: 2304-30-5), its molecular structure features four butyl groups attached to a phosphorus atom, with a chloride ion serving as the counterion. In terms of physical properties, it is likely to be stable under normal conditions, but it may be hygroscopic, meaning it readily absorbs moisture from the air. Its solubility in different solvents has not been fully characterized, but it is likely soluble in organic solvents.
TBPC finds applications as a phase-transfer catalyst, enabling reactions to occur between different phases that would not typically mix, such as water and organic solvents. Additionally, TBPC serves as an intermediate in the synthesis of other chemical compounds.
|
|
|
|
Chemical Formula |
C16H36ClP |
|
Exact Mass |
294.22 |
|
Molecular Weight |
294.89 |
|
m/z |
294.22 (100.0%), 296.22 (32.0%), 295.23 (17.3%), 297.22 (5.5%), 296.23 (1.4%) |
|
Elemental Analysis |
C, 65.17; H, 12.31; Cl, 12.02; P, 10.50 |
Organic Synthesis: High-efficiency Phase Transfer Catalyst
Catalysis in Heterogeneous Reactions
As a quaternary phosphonium salt phase transfer catalyst, tetrabutylphosphonium chloride acts as an indispensable core auxiliary in organic synthesis. In contrast to traditional quaternary ammonium salt catalysts, TBPC possesses stronger thermal stability, higher catalytic activity and superior acid-alkali resistance, fitting harsh reaction systems with high temperatures and strong corrosivity.
In heterogeneous organic synthesis, aqueous nucleophilic reagents and organic-phase substrates fail to fully contact due to phase separation, leading to extremely low reaction rates or even complete reaction inhibition.
Benefiting from its amphipathic structure, TBPC efficiently transports nucleophilic anions such as cyanide, hydroxide and thiocyanate from the aqueous phase into the organic phase. TBPC greatly improves two-phase contact efficiency and markedly accelerates core reactions including substitution, addition and condensation. At present, this catalyst is widely deployed in the synthesis of fine chemicals such as esters, ethers and acid chlorides, effectively resolving prevalent industrial drawbacks of conventional processes: sluggish reaction rates, low conversion rates and abundant by-product formation.
Compatibility with High-temperature and Specialized Reactions
Conventional quaternary ammonium catalysts tend to decompose and lose efficacy above 120 °C, whereas TBPC features a thermal decomposition temperature higher than 340 °C, enabling its use in high-temperature organic synthesis. TBPC exhibits remarkable catalytic performance in polymer monomer synthesis, aromatic compound modification and halide displacement reactions.
When applied as a catalyst for fine synthesis of pharmaceutical intermediates and pesticide technical materials, TBPC effectively enhances product selectivity, reduces isomeric impurities and raises the purity and yield of finished goods. In addition, the catalyst can be recovered and reused; its catalytic activity barely declines after simple extraction and drying treatment, significantly cutting raw material costs for fine chemical manufacturing and satisfying the demands of large-scale industrial production.
Advanced New Materials: Precursor of Ionic Liquids and Functional Additive
Raw Material for Synthesizing Functional Ionic Liquids
TBPC is a core precursor for preparing functional quaternary phosphonium ionic liquids. Via anion exchange reactions, TBPC can combine with various anions such as bromide, iodide, hexafluorophosphate and tetrafluoroborate to produce phosphonium-based ionic liquids with differentiated performance. Characterized by low volatility, high electrical conductivity, excellent thermal stability and wide electrochemical windows, such ionic liquids represent a hot research topic in the field of green new materials.
Compared with imidazolium and pyridinium ionic liquids, phosphonium ionic liquids derived from TBPC boast stronger temperature tolerance and weaker corrosiveness. They are extensively applied in electrochemical energy storage, gas separation, organic catalysis and material modification, providing vital support for the R&D and production of new energy and eco-friendly materials.
Auxiliary Agent for Preparing Inorganic Functional Materials
In the fabrication of inorganic nanomaterials and metal phosphide materials, TBPC serves as both a phosphorus source and a structure-directing agent to regulate material morphology, particle size and crystal structure.
During the synthesis of catalytic materials such as cobalt phosphide and nickel phosphide, using TBPC as a precursor enables uniform phosphorization at low temperatures, yielding metal phosphide nanomaterials with homogeneous particle size and outstanding catalytic activity.
TBPC can also function as a surface modifier to treat nanopowder surfaces, improving powder dispersibility in organic systems and eliminating agglomeration. This effectively boosts the mechanical properties and stability of composite materials, supporting wide applications in ceramic materials, catalytic carriers and new energy electrode materials.
Chemical Industry & Environmental Protection: Auxiliary for Desulfurization, Decarbonization and Wastewater Treatment
Purification of Industrial Flue Gas
Tetrabutylphosphonium chloride demonstrates exceptional adsorption capacity for acidic gases, enabling efficient capture of harmful acidic gases including sulfur dioxide, carbon dioxide and hydrogen sulfide from industrial flue gas as a novel eco-friendly flue gas purification additive. Its phosphonium cations form stable weak coordination complexes with acidic gas molecules to realize highly selective gas adsorption. After adsorption saturation, rapid desorption can be achieved via heating or pressure reduction, allowing cyclic reuse without secondary pollution.
Different from traditional amine-based desulfurizers, TBPC is non-volatile, non-toxic and thermally stable, avoiding secondary flue gas contamination while delivering superior desulfurization and decarbonization efficiency. TBPC adapts to ultra-low emission upgrading projects for thermal power, metallurgy, chemical and other industries, facilitating compliance with environmental production standards.
Treatment of Industrial Wastewater
In wastewater treatment for fine chemical and electroplating industries, TBPC acts as a flocculant and heavy metal chelating auxiliary to treat wastewater containing heavy metal ions and organic pollutants.
The alkyl chains in its molecular structure provide hydrophobicity, while phosphonium cations bind to negatively charged organic contaminants, colloidal particles and heavy metal complex anions in water to promote flocculation and sedimentation, rapidly removing organics, chromium, lead, mercury and other hazardous pollutants from wastewater.
Furthermore, this auxiliary exhibits better biodegradability than traditional polymer flocculants with extremely low residual content and no secondary water pollution. It suits high-standard industrial wastewater treatment and reclaimed water reuse scenarios, combining environmental friendliness and practical performance.
Electrochemistry and Anti-corrosion Fields: Functional Additives
Functional Additives for Electrochemical Systems
Possessing favorable electrical conductivity and electrochemical stability, TBPC can be used as an electrolyte additive in supercapacitors, lithium batteries and electroplating electrolyte systems. When added in trace amounts to supercapacitor electrolytes, it accelerates ion migration rates, broadens the electrochemical window, and elevates capacitor capacity and cycle service life.In metal electroplating processes, TBPC works as a leveling and brightening agent for plating baths, homogenizing metal ion deposition rates and refining coating grains.
The resulting metal coating becomes smoother and denser with enhanced corrosion resistance and surface gloss, finding broad application in hardware electroplating and plating of precision electronic components.
Metal Corrosion Inhibitor
For anti-corrosion applications in petrochemical engineering, pipeline transportation and industrial equipment, TBPC functions as an efficient and eco-friendly metal corrosion inhibitor. Its molecules adsorb onto the surfaces of carbon steel, stainless steel, copper and other metals to form a dense hydrophobic protective film that isolates oxygen, water vapor and acidic corrosive media, effectively suppressing electrochemical and chemical corrosion of metals.
In contrast to conventional sulfur-containing and nitrogen-containing corrosion inhibitors, this product is non-toxic, odorless, heat-resistant and highly efficient in corrosion inhibition. TBPC adapts to industrial operating conditions featuring high temperature, high humidity and strong corrosion, effectively extending the service life of industrial equipment and transmission pipelines and cutting equipment operation and maintenance costs. It boasts promising application prospects in oil and gas exploitation and anti-corrosion treatment of chemical equipment.
Other Auxiliary Applications in Fine Chemicals
Beyond the core fields mentioned above, TBPC can be used as a raw material for organic phosphating agents to synthesize high-end phosphine fine chemicals such as tetrabutylphosphonium antimonide arsenide. In coatings and ink industries, TBPC serves as a dispersing additive to improve the uniform dispersion of pigments and fillers, enhancing coating stability and brushing performance. Within biochemical engineering, it acts as a phase transfer auxiliary to facilitate biocatalytic reactions and raise bioconversion efficiency.
Endowed with integrated merits of stable molecular structure, excellent activity, low toxicity and environmental compatibility, TBPC has become a universal core auxiliary across fine chemicals, advanced new materials, environmental protection, new energy and multiple other sectors. Alongside the upgrading of high-end chemical industries, its application scenarios keep expanding continuously, and its market value is steadily rising.
Dominant Synthetic Process
Fundamental Reaction Mechanism
Tetrabutylphosphonium chloride is industrially produced mainly via the nucleophilic substitution quaternization reaction between tributylphosphine and 1-chlorobutane, a typical bimolecular nucleophilic substitution (SN2) reaction. This route currently delivers the highest production capacity and boasts the most mature process.
The core reaction principle is as follows: the phosphorus atom in tributylphosphine carries a lone electron pair and exhibits strong nucleophilicity. It attacks the electropositive alkyl carbon atom of 1-chlorobutane, breaking the carbon-chlorine bond and releasing chloride ions. Tetrabutylphosphonium cations are formed and subsequently combine with chloride ions to yield TBPC.
No strong acid or base catalyst is required for the whole reaction, which proceeds under mild conditions with minimal side reactions and high raw material conversion rates. Compatible with continuous industrial production, this process serves as the universal core synthetic route in the chemical industry.
Specific Operation Procedures and Parameter Control
Strict anhydrous and oxygen-free conditions are mandatory for this synthesis. Water drastically reduces reaction conversion and triggers hydrolytic side reactions that generate impurities. Anhydrous toluene is commonly adopted as an inert reaction solvent in production, featuring excellent solubility and superior chemical stability. It evenly disperses raw materials and stabilizes the system temperature.
Tributylphosphine and 1-chlorobutane are fed at a molar ratio of 1:1.05. A slight excess of 1-chlorobutane ensures complete conversion of the more costly tributylphosphine and cuts raw material losses. After charging the mixed raw materials into a sealed reactor, the mixture is continuously stirred and heated to 110–130 °C for reflux reaction lasting 18–24 hours. High-purity nitrogen is purged throughout the reaction to isolate oxygen and prevent oxidative degradation of raw materials.
Upon reaction completion, massive white crude products precipitate in the system. Atmospheric distillation is first carried out to remove toluene solvent and trace unreacted monomers, yielding crude TBPC. Purification is implemented by dissolving the crude product in acetone followed by recrystallization from diethyl ether to eliminate trace organic impurities and by-products. Final filtration and low-temperature vacuum drying afford refined TBPC with purity exceeding 99%.
Process Advantages and By-product Control
This synthetic process delivers extremely high reaction selectivity, with the principal reaction accounting for over 98% of the transformation. Minor by-products including dibutyl ether and phosphine oxides can be readily removed via recrystallization. Moreover, reaction parameters are highly controllable; minor fluctuations in temperature, material ratio and reaction duration barely affect product purity, ensuring outstanding production stability.
Compared with the traditional synthetic route using butanol and phosphorus trichloride, this catalyst-free process features fewer operation steps and lower moisture content in finished products, making TBPC suitable for high-end applications in electronics, pharmaceuticals and other sectors. Only a small volume of organic washing waste liquid is generated during manufacturing.
Solvents can be recovered and recycled by rectification, delivering both favorable environmental performance and economic benefits. Having fully replaced outdated conventional processes, TBPC stands as the preferred route for industrial mass production.
Spectroscopic, Safety, Storage and Transportation Properties
TBPC presents distinct qualitative spectroscopic signatures: characteristic stretching vibration peaks of alkyl C–H and C–P bonds can be detected via Infrared Spectroscopy (IR); ¹H and ¹³C NMR spectroscopy precisely resolve four sets of n-butyl carbon-hydrogen signals for structural verification of incoming materials.
Safety Profile
This product features low acute toxicity with mild irritation to skin and mucous membranes; prolonged direct contact should be avoided. TBPC must not be stored mixed with strong oxidants, active metals or concentrated strong alkalis. Though non-flammable, thermal decomposition at high temperatures releases corrosive fumes of phosphorus oxides and hydrogen chloride.
Storage and Transportation Requirements
Air isolation, moisture proofing and light shielding are mandatory during storage and transport. The product shall be hermetically packed in plastic-lined iron drums or glass reagent bottles, with storage temperature controlled below 30 °C. Hygroscopic materials can regain their original physicochemical properties after vacuum drying for dewatering, without irreversible deterioration.
Overall, TBPC integrates three core attributes: ionic conductivity, high thermal stability and tunable anions, which serve as the critical distinguishing characteristics from quaternary ammonium phase transfer catalysts.
Hot Tags: tetrabutylphosphonium chloride cas 2304-30-5, suppliers, manufacturers, factory, wholesale, buy, price, bulk, for sale, Thiazolyl Blue CAS 298 93 1, Caproaldehyde CAS 66 25 1, 3-Bromobiphenyl, Alanine CAS 107 95 9, Estradiol CAS 50 28 2, Cyclohexylboronic acid