Trifluoroacetic acid
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Trifluoroethanoic acid
TFA
-15.4 °C; 257.75 K
72.4 °C; 345.55 K
Trichloroacetic acid
materials in their standard state
(at 25 °C, 100 kPa)
Infobox references
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.
[edit] Uses
TFA is a reagent used frequently in organic synthesis because of a combination of convenient properties: volatility, solubility in organic solvents, and its strength.[1] 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.
[edit] Synthesis
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 (F2) develops is a mild reaction which leaves the carboxylic group intact.
