Fluorination

Fluorination is the introduction of fluorine into organic compounds with the help of fluorinating agents . It is a special case of halogenation .

In the respective reactions primarily be chlorine or - hydrogen - atoms replaced by fluorine atoms.

Fluorinating agents

Electrophilic fluorinating reagents

The following substances or groups of substances are used as fluorinating agents :

• gaseous fluorine
• Hydrogen fluoride
• Hydrofluoric pyridine - mixtures
• Alkali fluorides
• Aluminum fluoride
• quaternary ammonium fluorides
• Antimony fluoride
• Carboxylic acid fluorides
• Chromium fluoride
• Cobalt (III) fluoride
• Halogen fluorides (e.g. iodine pentafluoride )
• Molybdenum fluoride
• Mercury (I) fluoride
• Sulfur (IV) fluoride
• Silver fluoride
• Sulfonic acid fluorides
• Xenon fluoride and other noble gas compounds

Reactions

Swarts reaction

Fluoroalkanes or chlorofluoroalkanes can be obtained with the Swarts reaction . It is a variant of the Finkelstein reaction .

Silver, mercury (I) or potassium fluoride are used to replace the halogen atom with fluorine in monohalogen alkanes ( alkylmono halides ), eg. B.

${\displaystyle \mathrm {2\ R{-}X\ +\ Hg_{2}F_{2}\longrightarrow \ 2\ R{-}F\ +\ Hg_{2}X_{2}} }$

${\displaystyle \mathrm {(X\ {=}\ Cl,\ Br,\ I)} }$

Catalyzed fluorination

Technically, chlorofluoroalkanes are also obtained by fluorination of the corresponding chloroalkanes with hydrogen fluoride on fixed bed catalysts made from aluminum or chromium fluorides.

Schiemann reaction

Fluorinated aromatics are accessible with the Schiemann reaction .

Ion exchanger

Fluorine can also be introduced through quaternary ammonium fluorides bound to ion exchangers .

Electrofluorination / Simons process

The Electrofluorination is an electrochemical process that can be produced with the perfluorinated compounds.

In so-called Simons process in hydrogen fluoride dissolved in carboxylic acid or Sulfosäurefluoride are nickel - cells electrolyzed ( anodic fluorination), wherein a complete exchange of hydrogen takes place by fluorine.

Fluorotelomerization

In addition to electrofluorination, fluorotelomerization is another way of producing perfluorinated surfactants (PFT).

See also

• Fluoridation

swell

• H. Beyer, W. Walter: Textbook of organic chemistry . 20th ed., Hirzel, Stuttgart, 1984. pp. 135-136, 446.
• Entry to fluorination. In: Römpp Online . Georg Thieme Verlag, accessed on January 2, 2015.