4,4'-Difluorobenzophenone

Chembox new
ImageFile = 4,4'-Difluorobenzophenone.png Section1 = Chembox Identifiers
CASNo = 345-92-6
Section2 = Chembox Properties
Formula = C₁₃H₈OF
MolarMass = 218.20 g/mol
Appearance = Colorless Solid
MeltingPt = 107.5-108.5 °C
Section3 = Chembox Hazards
RPhrases =
SPhrases =

4,4’-difluorobenzophenone is a compound with the chemical formula of (FC₆H₄)₂CO. It is a colorless solid that is commonly used as a precursor to PEEK, or polyetherether ketone. PEEK is a semi-crystalline polymer that is insoluble in all materials except in harsh acidic conditions. Because PEEK is resistant to attack, it is commonly used in carbon fiber coatings and cable insulation.

ynthesis

The compound is prepared by condensation with "p"-fluorobenzoyl chloride and fluorobenzene with an aluminium chloride catalyst using a petroleum ether solvent. [cite journal | title = Preparation of Fluorbenzophenones | author = R.D. Dunlop and John H. Gardner | journal = J. Am. Chem. Soc. | year = 1933 | volume = 55 | issue = 4 | pages = 1665–1666 | doi = 10.1021/ja01331a058]

:FC₆H₅C(O)Cl + C₆H₅F → (FC₆H₄)₂CO + HCl

Uses

A derivative of 4,4’-difluorobenzophenone is used in the polymer PEEK, where 4,4'-difluorobenzophenone is used for polymerization across the fluorine-carbon bond when an oxygen anion is used to generate fluoride as the leaving group. PEEK is formed via condensation of 4,4’-difluorobenzophenone with 1,4-benzenediol. [“Polymers, High Temperature – Polyaryetherkeytones; Chapter 3”. Ullmann’s Encyclopedia of Industrial Chemistry. David Parker and Gary W. Wheatley. 2002, Wiley-VCH Verlag GmbH&Co. doi: 10.1002/14356007.a21_449]

:C₆H₄(OH)₂ + (FC₆H₄)₂CO → 1/n [(C₆H₄O₂)(C₁₃H₈O)] _n + 2HF

References