4,4'-Difluorobenzophenone
4,4’-Difluorobenzophenone is an organic compound with the formula of (FCH)CO. This colorless solid is commonly used as a precursor to PEEK, or polyetherether ketone, a so-called high performance polymer. Because PEEK is resistant to attack, it is commonly used in carbon fiber coatings and cable insulation. Synthesis. 4,4’-Difluorobenzophenone is prepared by the acylation of fluorobenzene with "p"-fluorobenzoyl chloride. The conversion is typically conducted in the presence of an aluminium chloride catalyst in a petroleum ether solvent. Uses. The polymer PEEK is generated from the reaction of 4,4'-difluorobenzophenone with the salts of 1,4-benzenediol.