What Is Benzophenone?
Benzophenone, a white or almost white crystalline powder, is notable for its sweet aroma. As a key aromatic ketone compound, it serves as an essential building block in organic chemistry, often referred to as diphenyl ketone.
Properties of Benzophenone
With a melting point of 48~50°C and a boiling point of 305.4°C, benzophenone exhibits significant thermal stability. Its flash point is 143°C, and it has a density of 1.11 g/cm3. Soluble in acetone and ethanol, it remains virtually insoluble in water. Structurally, it comprises two benzene rings linked by a carbonyl group, known as Ph2CO, with a molecular weight of 182.22 and CAS number 119-61-9.
Uses of Benzophenone
1. Photoinitiator
Its ability to absorb ultraviolet light makes it an effective photoinitiator in polymerization processes.
2. UV Absorber
Benzophenone-based UV absorbers protect plastics and paints from UV damage by converting UV light into less harmful forms of energy.
3. Preparation of Dehydrated Solvents
It is utilized alongside sodium metal to dehydrate solvents, with the blue color of benzophenone ketyl serving as an indicator for the dehydration process completion.
4. Photoaffinity Probe
In chemical biology, benzophenone is attached to small molecules to form covalent bonds with interacting proteins upon UV irradiation, aiding in the identification of protein interactions.
5. Other Uses
Derivatives of benzophenone find use as sunscreen ingredients, in organic synthesis, and as intermediates for pharmaceuticals.
Other Information on Benzophenone
1. Production Methods
Commercially, benzophenone is produced via the copper-catalyzed oxidation of diphenylmethane. Laboratory synthesis can involve hydrolysis of dichlorodiphenylmethane or the Friedel-Crafts reaction of benzoyl chloride with benzene.
2. Regulatory Information
Benzophenone is recognized as a hazardous substance under various laws, requiring careful management and handling according to various safety regulations.
3. Handling and Storage Precautions
Precautions include storing in a cool, dark place, using protective gear, and adhering to safe handling practices to prevent dust dispersion and avoid skin or eye contact.