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Trifluoroacetic acid (TFA) is the chemical compound with the formula CF3CO2H. It is a strong carboxylic acid due to the influence of the three very electronegative fluorine atoms. Relative to acetic acid, TFA is almost 100,000-fold more acidic. TFA is widely used in organic chemistry.
TFA is a reagent
used frequently in organic synthesis
because of a combination of convenient properties: volatility, solubility in organic solvents, and its strength. It is also less oxidizing than sulfuric acid
but more readily available in anhydrous form than hydrochloric acid
. One complication to its use is that TFA forms an azeotrope
with water with a boiling point of 105 °C.
It is also used as a ion pairing agent in liquid chromatography for separation of organic compounds, particularly peptides and small proteins. It is a versatile solvent for NMR spectroscopy (for materials stable in acid).
The derived acid anhydride, [CF3C(O)]2O, is a common reagent for introducing the trifluoracetyl group.
Electrofluorination of acetic acid
with the Simons method
is the best way to obtain trifluoroacetic acid. The anodic
reaction of the electrolysis
of a mixture of hydrogen fluoride
and acetic acid below the voltage at which elemental fluorine
) develops is a mild reaction which leaves the carboxylic group