Tri-tert-butylphosphine
[CAS# 13716-12-6]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: Tri-tert-butylphosphine
• Synonyms: Tris(1,1-dimethylethyl)phosphine
• Molecular Formula: C₁₂H₂₇P
• Molecular Weight: 202.32
• CAS Registry Number: 13716-12-6
• EC Number: 237-266-4
• SMILES: CC(C)(C)P(C(C)(C)C)C(C)(C)C

Properties

• Density: 0.82
• Melting point: 30 °C
• Boiling point: 102-103 °C (13 mmHg)
• Flash point: -17 °C
• Water solubility: insoluble

Safety Data

• Hazard Symbols: GHS02;GHS05 Danger
• Risk Statements: H250-H314-H318
• Safety Statements: P210-P222-P231-P233-P260-P264-P264+P265-P280-P301+P330+P331-P302+P335+P334-P302+P361+P354-P304+P340-P305+P354+P338-P316-P317-P321-P363-P370+P378-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Pyrophoric solids	Pyr. Sol.	1	H250
Serious eye damage	Eye Dam.	1	H318
Pyrophoric liquids	Pyr. Liq.	1	H250
Flammable liquids	Flam. Liq.	2	H225
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Substances or mixtures corrosive to metals	Met. Corr.	1	H290

• Transport Information: UN 2846

Discovery and Applications

Tri-tert-butylphosphine (TTBP) is an important organophosphorus compound that was first synthesized and characterized in the mid-20th century when chemists were exploring new phosphorus-based ligands and reagents. The synthesis of this compound involves the reaction of tert-butylmagnesium chloride with phosphorus trichloride, followed by purification to obtain pure TTBP. Its discovery marked a major advance in phosphine chemistry, providing enhanced steric protection and reactivity control in various chemical transformations.

The molecular formula of tri-tert-butylphosphine is C₉H₁₈P, which consists of a phosphorus atom bonded to three tert-butyl groups (-C(CH₃)₃). This structure creates significant steric hindrance around the phosphorus center, affecting its reactivity and coordination behavior. TTBP is a colorless liquid at room temperature with a characteristic odor. It is soluble in nonpolar solvents such as benzene, toluene, and dichloromethane, facilitating organic reactions and solution phase chemistry. TTBP exhibits nucleophilic and reducing properties due to the electron-donating nature of the tert-butyl groups. It readily coordinates with transition metals and metalloids to form stable complexes for use in catalytic processes and semiconductor applications.

TTBP complexes with transition metals such as palladium (Pd) or platinum (Pt) are effective catalysts for hydrogenation reactions. These catalysts promote the selective reduction of alkenes, alkynes, and carbonyl compounds under mild conditions and have advantages in synthetic organic chemistry. TTBP-based palladium catalysts are used in cross-coupling reactions to promote the formation of carbon-carbon bonds (e.g., Suzuki-Miyaura coupling). These reactions are essential in drug synthesis and materials science for building complex organic molecules and functional materials.

TTBP is used as a precursor for the production of doped semiconductors. It helps in the incorporation of phosphorus atoms into silicon (Si) or germanium (Ge) matrices, thereby modifying their electronic properties for use in semiconductor devices. Doped semiconductors have enhanced conductivity and tailored electrical properties, which are essential for integrated circuits and electronic devices. TTBP-based compounds are used for surface passivation of semiconductor materials, mitigating surface defects and improving device performance. Passivation layers improve the stability and reliability of semiconductor devices, especially in light-emitting diodes (LEDs), solar cells, and microelectronic components.

TTBP acts as a mild reducing agent in organic synthesis, facilitating the conversion of functional groups such as carbonyls (e.g., ketones, aldehydes) into the corresponding alcohols. The controlled reactivity of TTBP ensures high yields and selectivity in these transformations, supporting the production of pharmaceutical intermediates and fine chemicals.

References

2023. Synthesis, crystal structure, and biological activity of menthol-based chiral quaternary phosphonium salts (CQPSs). Structural Chemistry.
DOI: 10.1007/s11224-023-02259-0

2023. Miniaturization of popular reactions from the medicinal chemists’ toolbox for ultrahigh-throughput experimentation. Nature Synthesis.
DOI: 10.1038/s44160-023-00351-1

2023. Design and Application of Novel Sterically Hindered Phosphonium Salts in the Development of Functional Materials. Russian Journal of General Chemistry, 93(17).
DOI: 10.1134/s1070363223170036

2024. Thermal Decomposition of the Complex [tBu3PH][HB(C6F5)3]. Russian Journal of General Chemistry, 94(14).
DOI: 10.1134/s1070363224140056

2024. Study of photophysical properties in bronsted acids for nitrogen atoms with different hybrid (sp, sp2, sp3) orbitals. Journal of the Iranian Chemical Society.
DOI: 10.1007/s13738-024-03048-0