Trifluoroacetic acid
IUPAC name	2,2,2-Trifluoroacetic acid
Other names	Perfluoroacetic acid Trifluoroethanoic acid TFA
Identifiers
CAS number	76-05-1 Y
RTECS number	AJ9625000
SMILES	FC(F)(F)C(O)=O
ChemSpider ID	10239201
Properties
Molecular formula	C2HF3O2
Molar mass	114.02 g/mol
Appearance	colorless liquid
Density	1.5351 g/cm3, 20 °C
Melting point	-15.4 °C, 258 K, 4 °F
Boiling point	72.4 °C, 346 K, 162 °F
Solubility in water	miscible
Acidity (pKa)	0.3
Hazards
MSDS	External MSDS
R-phrases	R20 R35 R52/53
S-phrases	S9 S26 S27 S28 S45 S61
NFPA 704	1 3 1
Flash point	-3 °C
Related compounds
Related compounds	Acetic acid Trichloroacetic acid Perfluorononanoic acid
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Trifluoroacetic acid (TFA) is the simplest stable^[1] perfluorinated carboxylic acid chemical compound with the formula CF₃CO₂H. It is a strong carboxylic acid due to the influence of the electronegative trifluoromethyl group. TFA is almost 100,000-fold more acidic than acetic acid. TFA is widely used in organic chemistry.

Contents 1 Synthesis 2 Uses 2.1 As a solvent 3 References

[edit] Synthesis

Trifluoroacetic acid is prepared industrially by the electrofluorination of acetyl chloride and acetic anhydride, followed by hydrolysis of the resulting trifluoroacetyl fluoride:^[2]

CH₃COCl + 4 HF → CF₃COF + 3 H₂ + HCl

CF₃COF + H₂O → CF₃CO₂H + HF

An older route to TFA proceeds via the oxidation of 1,1,1-trifluoro-2,3,3-trichloropropene with potassium permanganate. The trifluorotrichloropropene can be prepared by Swarts fluorination of hexachloropropene.^[3]

[edit] Uses

TFA is the precursor to trifluoroacetic anhydride and 2,2,2-trifluoroethanol. It is a reagent used in organic synthesis because of a combination of convenient properties: volatility, solubility in organic solvents, and its strength as an acid.^[4]

Another use of TFA is in peptide synthesis, and related reactions where TFA is used as a strong acid to remove the t-butoxycarbonyl protecting group from boc-protected amines.

TFA is used to produce trifluoroacetate salts that serve as precursors to ceramic materials such as YBa₂Cu₃O_{7-x}.^[5]

[edit] As a solvent

It is also less oxidizing than sulfuric acid but more readily available in anhydrous form than many other acids. One complication to its use is that TFA forms an azeotrope with water (b. p. 105 °C). It is used in ion pairing agent in liquid chromatography of organic compounds, particularly peptides and small proteins. TFA is a versatile solvent for NMR spectroscopy (for materials stable in acid). It is also used as a calibrant in mass spectrometry.^[6]

[edit] References