Difference between revisions of "Trifluoroacetic acid"
|Line 117:||Line 117:|
Trifluoroacetic acid is a colorless volatile liquid, with a strong pungent acetic smell. It
Trifluoroacetic acid is a colorless volatile liquid, with a strong pungent acetic smell. It miscible with waterand organic solvents.
Revision as of 17:28, 13 July 2019
| IUPAC name
| Preferred IUPAC name
| Other names
|Molar mass||114.02 g/mol|
|Odor||Strong pungent odor|
|Density|| 1.531 g/cm3 (20 °C)|
1.489 g/cm3 (25 °C)
|Melting point||−15.4 °C (4.3 °F; 257.8 K)|
|Boiling point||72.4 °C (162.3 °F; 345.5 K)|
|Solubility||Miscible with acetone, benzene, carbon tetrachloride, diethyl ether, ethanol, hexane|
|Vapor pressure||82.5 mmHg (20 °C)|
|Safety data sheet||Sigma-Aldrich|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
|200 mg/kg (rat, oral)|
| Acetic acid|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Trifluoroacetic acid (TFA) is an organofluorine compound, an organic acid with the formula CF3COOH. TFA is an analogue of acetic acid, with the three hydrogen atoms replaced by three fluorine atoms. The acidity of TFA is approximately 34,000 times stronger than that of acetic acid due to the electronegativity of the trifluoromethyl group.
Trifluoroacetic acid reacts with bases to form trifluoroacetate salts.
- CF3COOH + MOH → CF3COOM + H2O
Trifluoroacetic acid is a colorless volatile liquid, with a strong pungent acetic smell. It reacts with bases and amines, while miscible with water and organic solvents.
TFA is sold by various chemical suppliers.
- CH3COCl + 4 HF → CF3COF + 3 H2 + HCl
- CF3COF + H2O → CF3COOH + HF
An older route to TFA involves the oxidation of 1,1,1-trifluoro-2,3,3-trichloropropene with potassium permanganate, the latter being prepared by Swarts fluorination of hexachloropropene.
Oxidation of 1,1,1-trifluoroethane aka R-143a, a freon commonly used as refrigerent and propellant in canned air products will also yield TFA. The oxidation is done by mixing R-143a with air and passing the mixture through an electric discharge of 15,000 V. Water vapor is used as carrying medium, which also helps preventing the degradation of TFA and unreacted R-143a.
- Make copper (II) trifluoroacetate
- Make trifluoroacetic anhydride
- Make 2,2,2-trifluoroethanol
- Make holmium trifluoroacetate
TFA is corrosive and should be handled with proper protection, in well ventilated areas.
Trifluoroacetic acid should be kept in closed bottles, away from heat and light, in a corrosive acid cabinet. Don't store it near ammonia or other volatile chemicals.
Trifluoroacetic acid can be neutralized with a base. Trifluoroacetates have low toxicity and generally do not require special disposal.