2,2',4,4'-Tetramethyl diphenyl disulfide is a highly hindered aromatic disulfide carrying four methyl groups at positions 2, 2', 4 and 4'. The compound is air- and photo-stable, freely soluble in hot ethanol, ethyl acetate and toluene, and practically insoluble in water. Commercial material is supplied ≥98 % pure.
Key physicochemical data:
Melting point: 142–144 °C (lit.)
Predicted boiling point: 412 °C / 760 mmHg
Density: 1.12 g cm⁻³ (20 °C, solid)
Flash point: >200 °C
Log P (octanol/water): 6.2 (predicted)
Typical uses:
High-temperature lubricant antioxidant and extreme-pressure (EP) anti-wear additive for gear oils and greases.
Building block for tetramethyl-diphenyl sulfoxide/sulfone high-performance plasticisers and flame retardants.
Model substrate for mechanistic studies on sterically encumbered C–S bond activation and radical thiol–disulfide exchange.
Quality specification (commercial grade):
Purity (GC): ≥98 %
Water content (KF): ≤0.2 %
Free thiol (as xylyl-SH): ≤0.1 %
Residue on ignition: ≤0.1 %
Heavy metals: ≤20 ppm
Hazard statement:
Causes skin and eye irritation (H315 + H319). Avoid inhalation of dust; use gloves, goggles and adequate ventilation. Store in a cool, dry place away from oxidants. SDS available on request.
