Chemical name: Methyltriphenylphosphonium Bromide
CAS number: 1779-49-3

product sheet

Description and Features
Catonium MTPB (Methyltriphenylphosphonium Bromide) is white crystal powder, its chemical formula is C19H18BrP. MTPB is a quaternary phosphonium salt mainly used in organic synthesis as a wittig reagent and as a phase transfer catalyst in the production of Powder Coatings. This material is highly soluble in water and polarizable solvents.

Methyltriphenylphosphonium Bromide is also known as MTPB, Triphenyl phosphate bromide and triphenylmethylphosphonium.

Compared to amines, imidazoles and quaternary ammonium salts CatOnium MTPB features considerable better latency and thermal stability. Further it offers a low odor, minimal color formation and controlled reactivity.

Product Information

CAS number1779-49-3
EC number 217-218-9
HS code2931 39 90
Molecular weight357.22 g/mol

Molecular and structural information

Molecular formulaC19H18BrP
Molecular weight357.22 g/mol
Smiles notation[Br-].C[P+](c1ccccc1)(c2ccccc2)c3ccccc3
Structural formula:phenylphosphonium bromide


AppearanceWhite crystal powder
Assay≥ 98.00 %
Melting Point230 - 234 °C
Loss on drying ≤ 0.20 %
Triphenyl phosphine≤ 0.50 %
Ash≤ 0.30 %

Physicochemical Information

Bulk density285 - 320 kg/m3
Flash point>240 ºC
Melting point 230 - 234 ºC
Partition coefficient (log Pow)-0.58
pH value6.0 - 6.5 (400 g/l, H₂O, 20 °C)
Vapor pressure0.0000002 hPa
Solubility in water400 g/l (25 ºC)

CatOnium MTPB (Methyltriphenylphosphonium Bromide) is being used in: (powder) coatings.

Available packaging: 20 KG / 25 KG carton drums.
Special packaging is available on request.

Shipment Info
Europe and United States: Provided CatOnium BTBP is on stock in our local warehouses our lead time is about one week if delivered in 20 KG drums.
Canada, South America, South Africa and other markets can also be served, please contact our sales department for more details.

Store Methyltriphenylphosphonium bromide in a cool, dry and well-ventilated area and in line with legal requirements.
Keep MTPB away from heat sources and oxidizing agents.

This substance (CAS: 1779-49-3) has been pre-registered under REACH (EC) 1907/2006.

A Material Safety Data Sheets (MSDS) is available for CatOnium MTPB and all other products supplied by Vesta Intracon BV. An MSDS describes the hazards of a product and explains how a product can be safely handled, used and stored. Besides it provides important regulatory and emergency response information for the purchased product.

Methyltriphenylphosphonium bromide: Disclaimer. This information is supplied solely for informational purposes and Vesta Intracon bv makes no guarantees or warranties, either expressed or implied, with respect to the accuracy and use of this data. All product warranties and guarantees shall be governed by the Standard Terms of Sale. Nothing in this document is legal advice or is a substitute for competent legal advice.