Triethylphosphine
[CAS# 554-70-1]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: Triethylphosphine
• Molecular Formula: C₆H₁₅P
• Molecular Weight: 118.16
• CAS Registry Number: 554-70-1
• EC Number: 209-068-8
• SMILES: CCP(CC)CC

Properties

• Density: 0.802
• Melting Point: -88 °C
• Boiling point: 127-128 °C
• Refractive index: 1.456
• Flash point: -17.2222 °C

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS07 Danger
• Risk Statements: H224-H225-H250-H302-H314-H318
• Safety Statements: P210-P222-P231-P233-P240-P241-P242-P243-P260-P264-P264+P265-P270-P280-P301+P317-P301+P330+P331-P302+P335+P334-P302+P361+P354-P303+P361+P353-P304+P340-P305+P354+P338-P316-P317-P321-P330-P363-P370+P378-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Pyrophoric liquids	Pyr. Liq.	1	H250
Skin corrosion	Skin Corr.	1B	H314
Flammable liquids	Flam. Liq.	2	H225
Flammable liquids	Flam. Liq.	1	H224
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1A	H314

• Transport Information: UN 2845

Discovery and Applications

Triethylphosphine is a versatile organophosphorus compound recognized for its significant role in various chemical applications. This compound, with the chemical formula (C2H5)3P, features a phosphorus atom bonded to three ethyl groups. Its discovery and subsequent applications underscore its importance in the fields of catalysis, coordination chemistry, and organic synthesis. This article provides an overview of the discovery, applications, and utility of triethylphosphine in modern chemical research and industry.

Triethylphosphine was first synthesized in the early 20th century as chemists explored new organophosphorus compounds. The compound is typically prepared by the reaction of phosphorus trichloride with ethanol or ethyl alcohol in the presence of a base, such as sodium hydroxide. This synthesis yields triethylphosphine as the primary product, which can then be purified and used for various applications. The straightforward synthesis and the stable nature of triethylphosphine have made it a valuable reagent in both academic and industrial settings.

One of the primary applications of triethylphosphine is in the field of catalysis. The compound acts as a ligand in the formation of metal complexes, particularly with transition metals such as palladium, platinum, and nickel. These metal-ligand complexes are crucial for numerous catalytic processes, including cross-coupling reactions, hydrogenation, and carbonylation. Triethylphosphine is favored for its ability to stabilize metal centers and influence the electronic properties of the metal, leading to improved catalytic efficiency and selectivity.

In coordination chemistry, triethylphosphine is used to synthesize a variety of metal complexes with different coordination environments. Its three ethyl groups provide a significant steric bulk, which affects the geometry and reactivity of the resulting metal complexes. This steric influence is valuable in designing complexes with specific properties, such as enhanced reactivity or selectivity for particular reactions.

Triethylphosphine also finds application in organic synthesis, where it serves as a nucleophile and a reducing agent. Its ability to participate in nucleophilic substitution reactions makes it useful for modifying organic molecules and constructing complex structures. Additionally, triethylphosphine can act as a reducing agent in various chemical transformations, including the reduction of organic halides and other functional groups.

The compound's properties include its volatility and relatively low toxicity, making it convenient for use in laboratory settings. Triethylphosphine is generally handled with standard safety precautions, including working in a well-ventilated area and using appropriate personal protective equipment. Proper storage conditions are also essential to maintain the stability of the compound, typically in a cool, dry place.

Future research on triethylphosphine may explore its potential in developing new catalytic systems and materials. Advances in understanding its interaction with different metal centers and its behavior in various chemical environments could lead to innovative applications and enhanced performance in existing catalytic and synthetic processes.

References

2024. On Phosphine-containing Gold(I) Complexes in Solution and Their Biological Application. Russian Journal of Inorganic Chemistry.
DOI: 10.1134/s0036023624600965

2023. Synthesis, Structure, and Catalytic Properties of Palladium(II) bis(diphenylcyclohexylphosphine) (ζ5-cyclopentadienyl) Tetrafluoroborate in Butadiene Telomerization with Methanol. Journal of Structural Chemistry.
DOI: 10.1134/s0022476623110203

2023. Reaction of 2-R-naphtho[2,3-d][1,3,2]dioxaphosphinin-4-ones with arylidene derivatives of malonic acid esters: synthesis, molecular and crystal structures of 5-oxo-2-R-naphtho[2,3-f][1,2]oxaphosphepine 2-oxides. Russian Chemical Bulletin.
DOI: 10.1007/s11172-023-3865-2