Benzophenone Identifiers CAS number PubChem ChemSpider UNII DrugBank KEGG ChEBI ChEMBL Jmol-3D images Image 1 Properties Molecular formula C13H10O Molar mass 182.217 g/mol Appearance White solid Density 1.11 g/cm3, solid Melting point
Solubility in water Insoluble Solubility Benzene, THF, ethanol, propylene glycol Hazards MSDS External MSDS by JT Baker Main hazards Harmful (XN) NFPA 704 (what is: /?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Benzophenone can be used as a photo initiator in UV-curing applications such as inks, imaging, and clear coatings in the printing industry. Benzophenone prevents ultraviolet (UV) light from damaging scents and colors in products such as perfumes and soaps. It can also be added to the plastic packaging as a UV blocker. Its use allows manufacturers to package the product in clear glass or plastic. Without it, opaque or dark packaging would be required.
In biological applications, benzophenones have been used extensively as photophysical probes to identify and map peptide–protein interactions .
Benzophenone can be prepared by the reaction of benzene with carbon tetrachloride followed by hydrolysis of the resulting diphenyldichloromethane, or by Friedel-Crafts acylation of benzene with benzoyl chloride in the presence of a Lewis acid (e.g. aluminium chloride) catalyst. The industrial synthesis relies on the copper-catalyzed oxidation of diphenylmethane with air.
Benzophenone is a common photosensitizer in photochemistry. It crosses from the S1 state into the triplet state with nearly 100% yield. The resulting diradical will abstract a hydrogen atom from a suitable hydrogen donor to form a ketyl radical.
Benzophenone radical anion
Sodium reduces benzophenone to the deeply colored radical anion, diphenylketyl:
- Na + Ph2CO → Na+Ph2CO·−
This ketyl is used in the purification of hydrocarbon solvents, because it reacts with water and oxygen to give non-volatile products. The ketyl is soluble in the organic solvent being dried, so it reacts quickly with residual water and oxygen. In comparison, sodium is insoluble, and its heterogeneous reaction is much slower. The ketyl radical generally appears blue or purple, depending on the solvent.
Commercially significant derivatives
Substituted benzophenones such as oxybenzone and dioxybenzone are used in some sunscreens. The use of benzophenone-derivatives which structurally resemble a strong photosensitizer has been strongly criticized (see sunscreen controversy).
The high-strength polymers PEEK, polyetherether ketones, are prepared from derivatives of benzophenone.
- ^ Dorman, Gyorgy; Prestwich, Glenn D. (1 May 1994). "Benzophenone Photophores in Biochemistry". Biochemistry 33 (19): 5661–5673. doi:10.1021/bi00185a001.
- ^ Marvel, C. S.; Sperry, W. M. (1941), "Benzophenone", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0095 ; Coll. Vol. 1: 95
- ^ Hardo Siegel, Manfred Eggersdorfer "Ketones" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, 2002 by Wiley-VCH, Wienheim. DOI: 10.1002/14356007.a15_077
- ^ W. L. F. Armarego and C. Chai (2003). Purification of laboratory chemicals. Oxford: Butterworth-Heinemann. ISBN 0750675713.
- ^ Knowland, John; McKenzie, Edward A.; McHugh, Peter J.; Cridland, Nigel A. (1993). "Sunlight-induced mutagenicity of a common sunscreen ingredient". FEBS Letters 324 (3): 309–313. doi:10.1016/0014-5793(93)80141-G. PMID 8405372.
- Merck Index, 11th edition, 1108.
Toluene is refluxed with sodium and benzophenone to produce dry, oxygen-free toluene.
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benzophénone — ● benzophénone nom féminin Cétone C6H5―CO―C6H5 obtenue par action du chlorure de benzoyle sur le benzène. benzophénone [bɛ̃zofenɔn] n. f. ÉTYM. 1849; de benzo , phén(yle), et one, suff. spécifique des cétones. → Acétophénone. ❖ ♦ Chim. Cétone… … Encyclopédie Universelle
benzophenone — [ben΄zō fi nōn′, ben΄zōfē′nōn΄] n. [ BENZO + PHEN(OL) + ONE] a white, sweet smelling crystalline ketone, C6H5COC6H5, used as an intermediate compound in making flavorings, fragrances, etc … English World dictionary
benzophenone — noun Etymology: International Scientific Vocabulary benz + phen + one Date: 1877 a colorless crystalline ketone C13H10O used especially as a perfume fixative and in sunscreens; also a derivative of benzophenone … New Collegiate Dictionary
benzophenone — ben·zo·phe·none .ben zō fi nōn, fē .nōn n a colorless crystalline ketone C13H10O used chiefly in perfumery and sunscreens also a derivative of benzophenone * * * ben·zo·phen·one (ben″zo fenґōn) an aromatic ketone that is a component of … Medical dictionary
benzophenone — benzfenonas statusas T sritis chemija formulė (C₆H₅)₂CO atitikmenys: angl. benzophenone rus. бензофенон ryšiai: sinonimas – difenilketonas … Chemijos terminų aiškinamasis žodynas
benzophenone — /ben zoh fi nohn , fee nohn/, n. Chem. a crystalline, water insoluble ketone, C13H10O, used in organic synthesis. Also called diphenyl ketone. [1880 85; BENZO + PHEN + ONE] * * * … Universalium
benzophenone — noun a) Any of a class of aromatic ketones based on the parent compound diphenylketone (CH)CO; used, amongst other things, as ingredients in sunblock. b) The compound diphenylmethanone … Wiktionary