Diphenyl sulfide
[CAS# 139-66-2]

Identification

• Classification: Chemical reagent >> Organic reagent >> Thiol/thiophenol
• Name: Diphenyl sulfide
• Synonyms: Phenyl sulfide
• Molecular Formula: C₁₂H₁₀S
• Molecular Weight: 186.27
• CAS Registry Number: 139-66-2
• EC Number: 205-371-4
• SMILES: C1=CC=C(C=C1)SC2=CC=CC=C2

Properties

• Density: 1.113
• Melting point: -40 °C
• Boiling point: 296 °C
• Refractive index: 1.6317-1.6337
• Water solubility: insoluble

Safety Data

• Hazard Symbols: GHS07;GHS09 Warning
• Risk Statements: H302-H315-H400-H410
• Safety Statements: P264-P270-P273-P280-P301+P317-P302+P352-P321-P330-P332+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400

• Transport Information: UN 2810

Discovery and Applications

Diphenyl sulfide was first synthesized and characterized in the late 19th century during the study of aromatic sulfides. The compound is prepared by the reaction of phenylmagnesium bromide (PhMgBr) with elemental sulfur (S₈) or by the reaction of phenyl chloride (C₆H₅Cl) with sodium sulfide (Na₂S). This simple synthesis method makes it useful in a variety of industrial and laboratory applications.

Diphenyl sulfide has a sulfur atom double-bonded to two phenyl groups (-C₆H₅-S-C₆H₅). This structure gives both the aromaticity of the benzene ring and the characteristics of the sulfide. Compared to mercaptans, it is relatively less reactive towards oxidants and more stable in a variety of chemical environments. Diphenyl sulfide is a colorless to pale yellow crystalline solid at room temperature. It is slightly soluble in water, but freely soluble in organic solvents such as ethanol, acetone, benzene, and chloroform. Diphenyl sulfide is relatively inert under normal conditions, but can oxidize in the presence of strong oxidants to form diphenyl sulfoxide (Ph2SO) and diphenyl sulfone (Ph2SO2). It behaves as a weak base in aqueous solution and can be protonated to form the corresponding sulfonium salts.

Diphenyl sulfide is a widely used building block in the synthesis of pharmaceuticals and agrochemicals. It participates in various reactions to form complex organic molecules, including sulfide cross-coupling reactions and nucleophilic substitution reactions. Due to its chemical stability and lubricating properties, diphenyl sulfide is used as an additive in lubricants to improve performance under extreme conditions and reduce wear and friction in mechanical systems.

Diphenyl sulfide derivatives are used as flame retardants in polymers and textiles. These compounds improve fire resistance by forming a char layer that inhibits flame spread and reduces smoke emissions. Certain derivatives of diphenyl sulfide are used as intermediates in the production of dyes and pigments. These compounds impart bright colors to textiles, plastics, and other materials used in the textile and automotive industries.

Diphenyl sulfide is used as an analytical reagent for the detection and quantification of metal ions in solution. Its complexing properties with metals are useful for determining trace metal concentrations in environmental and biological samples.

In research applications, diphenyl sulfide derivatives have potential use in organic photovoltaic devices (solar cells). These studies explore their electronic properties and efficiency in converting sunlight into electricity.

References

2023. Synthesis and Structure of Diphenyl Oxide-Diphenyl Sulfide (Co)polyarylene Diphthalides and Their Copolymers with Styrene. Russian Journal of General Chemistry.
DOI: 10.1134/s1070363223140347

2023. Use of the Redox Properties of Hydrazine in the Synthesis of Organochalcogen Compounds (A Review). Russian Journal of General Chemistry.
DOI: 10.1134/s107036322314030x

2024. Organic Sulfur Derivatives and Their Metal Complexes as Promising Pharmacologically Active Compounds. Russian Journal of Coordination Chemistry.
DOI: 10.1134/s1070328423600894