Tetrabutylphosphonium Bromide

Tetrabutylphosphonium Bromide (TBPB) (CAS 3115-68-2) is a versatile quaternary phosphonium salt, widely recognized as a highly effective Phase-Transfer Catalyst (PTC). It typically appears as a white to off-white crystalline powder with minimal odor. Unlike the highly reactive tertiary phosphines, TBPB is a stable, non-volatile salt that efficiently transports anions (e.g., nucleophiles) from an aqueous or solid phase into an organic solvent phase. This capability significantly accelerates many difficult organic reactions by enabling reagents to meet and react faster. TBPB's robustness and thermal stability also make it a valuable precursor for preparing advanced ionic liquids.

Basic Information of TBPB

CAS No.:	3115-68-2
EC No.:	221-487-8
Linear Formula:	C16H36BrP
Molecular Weight:	339.33
Appearance:	White to off-white crystalline powder
Odor:	Little to none
Melting Point:	100-103 °C(lit.)
Density:	1.8[at 20℃]
Solubility:	Insoluble in water; soluble in alcohol, oils, and most organic solvents.
Flash Point:	290 °C
RIDADR:	UN 3464 6.1/PG 3
Chemical Structure:

Application Overview

TBPB's stability, low toxicity compared to other phosphonium salts, and powerful catalytic activity make it essential across diverse chemical and material science fields:

• Phase-Transfer Catalysis (PTC): Its primary role is in enabling two-phase reactions, facilitating nucleophilic substitutions (e.g., converting alkyl halides to nitriles or thiocyanates), oxidation, reduction, and polymerization reactions by bridging incompatible solvent systems (aqueous/organic).

• Ionic Liquid Precursor: The tetrabutylphosphonium cation is a key building block for synthesizing various room-temperature ionic liquids (ILs), where it imparts desirable properties like high thermal stability and low flammability to the resulting solvent.

• Polymerization Catalyst/Modifier: Used as a catalyst or co-catalyst in the synthesis of specialized polymers (e.g., polycarbonates, polyesters), where it can influence molecular weight and improve reaction kinetics.

• Nanomaterials Stabilization: Acts as a surface capping agent or stabilizing ligand for the preparation of certain metal nanoparticles, preventing aggregation and controlling size distribution.

• Electrochemistry: Employed as a supporting electrolyte in non-aqueous electrochemical studies due to its high solubility in polar organic solvents and its large, non-coordinating cation.

• High Catalytic Purity: We minimize the presence of residual water and inorganic salts (e.g., sodium bromide), which can interfere with the activity of the phosphonium cation. Our ultra-dry grade TBPB guarantees maximum catalytic efficiency, particularly in water-sensitive organic synthesis.

Hazards Classification

• GHS Classification: Acute Toxicity Oral (GHS06), Acute Toxicity Dermal (GHS07), Skin Irritation (GHS07), Eye Irritation (GHS07), Aquatic Chronic (GHS09)

• Hazard Statements: Harmful if swallowed; Harmful in contact with skin; Causes skin irritation; Causes serious eye irritation; Harmful to aquatic life with long lasting effects.

• UN Number: UN 3464

• Hazard Class: 6.1 (Toxic substances)

• Packing Group: III