Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide
[CAS# 75980-60-8]

Identification

• Classification: Chemical reagent >> Organic reagent >> Phosphorous compound
• Name: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide
• Synonyms: 2,4,6-Trimethyl benzoyldiphenyl phosphine oxide
• Molecular Formula: C₂₂H₂₁O₂P
• Molecular Weight: 348.37
• CAS Registry Number: 75980-60-8
• EC Number: 278-355-8
• SMILES: CC1=CC(=C(C(=C1)C)C(=O)P(=O)(C2=CC=CC=C2)C3=CC=CC=C3)C

Properties

• Melting point: 88-92 °C

Safety Data

• Hazard Symbols: GHS07;GHS08;GHS09 Warning
• Risk Statements: H317-H361-H411
• Safety Statements: P203-P261-P272-P273-P280-P302+P352-P318-P321-P333+P317-P362+P364-P391-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Reproductive toxicity	Repr.	2	H361
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin sensitization	Skin Sens.	1B	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Reproductive toxicity	Repr.	1B	H360
Skin sensitization	Skin Sens.	1	H317
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Reproductive toxicity	Repr.	1B	H360F
Reproductive toxicity	Repr.	2	H361f
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Reproductive toxicity	Repr.	1B	H360Fd
Respiratory sensitization	Resp. Sens.	1B	H334
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Reproductive toxicity	Repr.	2	H361fd
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Reproductive toxicity	Repr.	2	H361f

Discovery and Applications

Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, with the molecular formula C₁₈H₂₁O₂P, is a notable compound in the realm of photoinitiators used in polymer chemistry. This compound features a phosphorus atom bonded to two phenyl groups and a 2,4,6-trimethylbenzoyl group, which contributes to its unique chemical properties and applications. The synthesis of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide involves the reaction of diphenylphosphine oxide with 2,4,6-trimethylbenzoyl chloride, resulting in a phosphine oxide with enhanced reactivity.

One of the primary applications of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is as a photoinitiator in UV-cured polymer systems. When exposed to ultraviolet (UV) light, this compound generates free radicals that initiate the polymerization of acrylates, methacrylates, and other vinyl monomers. The resulting polymer networks exhibit excellent mechanical properties, chemical resistance, and durability, making them suitable for use in coatings, adhesives, and inks.

The effectiveness of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide as a photoinitiator is due to its high quantum yield and broad absorption spectrum in the UV region. This enables efficient initiation of polymerization processes even at relatively low concentrations. The compound’s ability to generate free radicals upon UV exposure makes it a valuable component in formulating UV-cured coatings and inks that require rapid curing and high performance.

In addition to its role in UV-curing applications, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is utilized in the development of high-performance composites and materials. Its photoinitiating properties facilitate the production of complex polymer matrices with controlled properties, such as enhanced thermal stability and mechanical strength. These materials find applications in aerospace, automotive, and electronics industries where performance under extreme conditions is critical.

The compound is also used in research and development settings to study the kinetics of photopolymerization and to develop new photoinitiator systems. Its ability to efficiently initiate polymerization reactions makes it a valuable tool for exploring new polymer formulations and understanding the fundamental mechanisms of UV curing.

Overall, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide is a versatile chemical compound with significant applications in polymer chemistry. Its role as a photoinitiator enables the development of advanced materials with desirable properties, contributing to innovations in coatings, adhesives, inks, and composites.

References

2024. Ultra-tough light-curing ionogels for UV shielding. Communications Materials, 5(1).
DOI: 10.1038/s43246-024-00702-1

2024. Influence of reactive diluent composition on properties and bio-based content of itaconic acid-based additive manufacturing materials. Discover Applied Sciences, 6(5).
DOI: 10.1007/s42452-024-05926-x

2024. Preparation of Si-O-C-Based Precursor Ceramics for Photo-Curing 3D Printing: Selection of Silicone Prepolymer System and Photoinitiator. Journal of Materials Engineering and Performance, 33(16).
DOI: 10.1007/s11665-024-09922-5