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Description and features

Catonium BTPB (Butyltriphenylphosphonium Bromide) is a white to off-white powder, its chemical formula is C22H24BrP. BTPB is a quaternary phosphonium salt mainly used in organic synthesis as a wittig reagent and as a phase transfer catalyst in the production of fluoroelastomers, Epoxy Resins and Powder Coatings. This material is highly soluble in water and polarizable solvents.

Butyltriphenylphosphonium Bromide is also known as BTPB, BTPPB and TPBP-Br.

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


Europe and United States: Provided CatOnium BTPB is on stock in our local warehouses our lead time is about one week if delivered in 25 KG fiber drums.

Canada, South America, South Africa and other markets can also be served, please contact our sales department for more details.

This substance (CAS: 1779-51-7) has been registered under REACH (EC) 1907/2006.

Product Identification

CAS number1779-51-7
EC number918-205-7
HS code2931 39 90


Appearance White to off white powder
Assay ≥98.00 %
Ash≤0.30 %
Loss on drying≤0.20 %
Triphenyl phosphine≤0.50 %


CatOnium BTPB (Butyltriphenylphosphonium Bromide) is being used in: (powder) coatings, (fluoro)elastomers and in epoxy resins.


Available packaging: 21.95 / 25 KG/ 50 KG fiber drums.
Special packaging is available on request.


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


A Material Safety Data Sheets (MSDS) is available for CatOnium BTBP and all other products supplied by Vesta Chemicals 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.

Molecular and structural information

Molecular formula C22H24BrP
Molecular weight 399.30 g/mol
Smiles notation Br.CCCCP(C1=CC=CC=C1)(C1=CC=CC=C1)C1=CC=CC=C1
Structural formula butyltriphenylphosphonium bromide

Physicochemical information

Boiling point No data available
Bulk densityNo data available
Flash point 255 ºC
Melting point 240 – 243 ºC
Partition coefficient (log Pow) 1.7846
Solubility in water Soluble
Vapor pressure No data available