Diphenyl sulfide is the simplest aromatic thio-ether, consisting of two benzene rings linked by a sulfur atom. The material is air- and photo-stable, miscible with all common organic solvents (dichloromethane, ethyl acetate, toluene, alcohols, ketones) and essentially insoluble in water (≈ 5 mg L⁻¹ at 25 °C).
Key physicochemical data:
Density: 1.113 g cm⁻³ (20 °C)
Refractive index n²⁰/D: 1.6327
Melting point: −18 °C
Boiling point: 296 °C (760 mmHg)
Flash point: 123 °C (closed cup)
Vapour pressure: 0.2 mmHg (25 °C)
Log P (octanol/water): 4.2
Typical uses:
High-temperature solvent and heat-transfer fluid for polyimide and polyester fibre manufacture.
Photoinitiator synergist for UV-curable inks, coatings and dental formulations (triplet energy donor).
Building block for diphenyl sulfoxide/sulfone plasticisers, flame retardants and agro-chemical intermediates.
Quality specification (commercial grade):
Purity (GC): ≥99 %
Water content (KF): ≤0.1 %
Free thiol (as PhSH): ≤0.05 %
Residue on ignition: ≤0.05 %
Heavy metals: ≤10 ppm
Hazard statement:
Combustible liquid (H226). Causes skin and eye irritation (H315 + H319). Avoid inhalation of vapour; use gloves, goggles and adequate ventilation. SDS available on request.
