4-Phenylbenzophenone is an aromatic ketone in which a benzoyl group is attached to the 4-position of a biphenyl core. The extended π-conjugation gives strong UV-A absorption (λmax ≈ 330 nm, log ε 3.9) and excellent thermal stability. It is practically insoluble in water (< 0.1 mg L⁻¹ at 25 °C), freely soluble in toluene, chloroform and THF, and can be recrystallised from ethanol. Commercial material is supplied at ≥ 99 % purity and remains stable for ≥ 2 years when stored at room temperature in tightly closed containers away from light.
Key Physicochemical Data:
Melting point: 99–101 °C
Boiling point: 419 °C / 760 mmHg
Density: 1.262 g cm⁻³ (0 °C)
Flash point: 184 °C (closed cup, predicted)
Log P (octanol/water): 4.83
Vapour pressure: 3×10⁻⁷ mmHg at 25 °C
Typical Uses:
High-performance photoinitiator for UV-curable inks, clear coatings, wood finishes and structural adhesives; especially suited for thick-section or pigmented systems .
Photosensitiser in the manufacture of photosensitive resins and printing plates .
Key intermediate for the synthesis of the antifungal drug bifonazole and other biphenyl-based bioactive molecules .
Quality Specification (Commercial Grade):
Purity (GC): ≥ 99 %
Water content (KF): ≤ 0.3 %
Free acid (as benzoic acid): ≤ 0.2 %
Residue on ignition: ≤ 0.1 %
Heavy metals: ≤ 20 ppm
Hazard Statement:
Causes skin and eye irritation (H315 + H319); harmful if swallowed (H302) or inhaled (H332) . Avoid dust formation; use gloves, goggles and adequate ventilation. Store in a cool, dry place away from oxidants and strong acids. SDS available on request.
