Diphenylphosphinyl chloride
[CAS# 1499-21-4]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: Diphenylphosphinyl chloride
• Synonyms: Diphenylphosphinic chloride; Chlorodiphenylphosphine oxide; DPP-Cl
• Molecular Formula: C₁₂H₁₀ClOP
• Molecular Weight: 236.64
• CAS Registry Number: 1499-21-4
• EC Number: 216-107-2
• SMILES: C1=CC=C(C=C1)P(=O)(C2=CC=CC=C2)Cl

Properties

• Water solubility: decomposes
• Density: 1.3±0.1 g/mL, Calc.^*, 1.242 g/mL (Espl.)
• Melting point: 20 °C (Expl.)
• Index of Refraction: 1.585, Calc.^*, 1.609 (Expl.)
• Boiling Point: 369.2±11.0 °C (760 mmHg), Calc.^*, 379.2 °C (Expl.)
• Flash Point: 177.1±19.3 °C, Calc.^*, 26 °C (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS02;GHS06;GHS07 Danger
• Risk Statements: H226-H314-H335
• Safety Statements: P210-P233-P240-P241-P242-P243-P260-P261-P264-P271-P280-P301+P330+P331-P302+P361+P354-P303+P361+P353-P304+P340-P305+P354+P338-P316-P319-P321-P363-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Flammable liquids	Flam. Liq.	3	H226
Specific target organ toxicity - single exposure	STOT SE	3	H335
Serious eye damage	Eye Dam.	1	H318

• Transport Information: UN 2920

Discovery and Applications

Diphenylphosphinyl chloride is an organophosphorus compound with the molecular formula (C₆H₅)₂P(O)Cl. It is a key intermediate in phosphorus chemistry, widely used in organic synthesis, materials science, and coordination chemistry. The compound is derived from diphenylphosphine oxide, a structurally similar phosphorus-based reagent, and has been studied for its reactivity in various chemical transformations.

The discovery of diphenylphosphinyl chloride is linked to the broader development of phosphorus oxychloride derivatives, which have been explored since the early 20th century in efforts to develop new phosphorylating reagents. Organophosphorus compounds gained significant interest in synthetic chemistry due to their versatility in modifying organic structures, particularly in the formation of phosphorus-carbon and phosphorus-oxygen bonds. Diphenylphosphinyl chloride was developed as part of this expanding field and has since become an important reagent in laboratory and industrial applications.

Diphenylphosphinyl chloride is primarily synthesized by the chlorination of diphenylphosphine oxide using chlorinating agents such as phosphorus oxychloride (POCl₃) or thionyl chloride (SOCl₂). The resulting compound is a moisture-sensitive, reactive phosphorus-based reagent that hydrolyzes in the presence of water to yield diphenylphosphinic acid and hydrogen chloride.

One of the key applications of diphenylphosphinyl chloride is in the synthesis of phosphine ligands used in coordination chemistry and catalysis. Phosphine ligands play a crucial role in stabilizing transition metal catalysts, which are widely employed in organic transformations such as cross-coupling reactions, hydrogenation, and carbon-carbon bond formation. The ability of diphenylphosphinyl chloride to introduce phosphorus functionality into organic molecules makes it valuable in ligand design and modification.

In addition to catalysis, diphenylphosphinyl chloride is used in the synthesis of organophosphorus compounds such as phosphonates and phosphine oxides. These compounds are applied in medicinal chemistry, where phosphorus-containing molecules have been explored for their potential biological activity. Phosphonates, for example, are key structural components in certain antiviral and anticancer drugs, making phosphorus-based reagents like diphenylphosphinyl chloride essential in pharmaceutical research.

Another important application of diphenylphosphinyl chloride is in materials science. It is employed in the modification of polymers and the development of flame-retardant materials. Organophosphorus compounds are known for their flame-resistant properties, and diphenylphosphinyl chloride serves as a precursor for phosphorus-based additives used in polymeric materials. These additives enhance the thermal stability and fire resistance of plastics and coatings, contributing to safety in various industries.

Diphenylphosphinyl chloride also finds use in the functionalization of organic molecules through phosphorylation reactions. It is used to introduce phosphinyl and phosphoryl groups, which can influence the physical and chemical properties of target compounds. This capability is particularly relevant in synthetic organic chemistry, where precise modifications are necessary to achieve desired reactivity and selectivity.

Due to its high reactivity, diphenylphosphinyl chloride must be handled with care. It is sensitive to moisture and decomposes upon exposure to water, releasing hydrogen chloride gas. Proper storage in dry conditions is essential to maintain its stability and effectiveness as a reagent. Safety precautions, including the use of protective equipment and well-ventilated workspaces, are necessary when handling this compound to prevent exposure to corrosive byproducts.

Diphenylphosphinyl chloride continues to be an important reagent in various fields of chemistry, particularly in the development of catalysts, pharmaceuticals, and advanced materials. Its role as a versatile phosphorus-based reagent ensures its continued relevance in synthetic and industrial applications.

References

2024. Low-Temperature Fabrication of Stable Black-Phase CsPbI3 Perovskite Flexible Photodetectors Toward Wearable Health Monitoring. Nano-Micro Letters, 16.
DOI: 10.1007/s40820-024-01565-4

2023. Phase Regulation and Defect Passivation Enabled by Phosphoryl Chloride Molecules for Efficient Quasi-2D Perovskite Light-Emitting Diodes. Nano-Micro Letters, 15.
DOI: 10.1007/s40820-023-01089-3

2021. A novel phthalazinone-based epoxy resin with excellent rheological property and intrinsic flame retardancy. Journal of Materials Science, 56, 26.
DOI: 10.1007/s10853-021-05863-9