Trifluoroacetic acid
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| Trifluoroacetic acid | |
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| General | |
| Systematic name | Trifluoroacetic acid |
| Other names | Perfluoroacetic acid Trifluoroethanoic acid TFA |
| Molecular formula | C2HF3O2 |
| SMILES | FC(F)(F)C(O)=O |
| Molar mass | 114.03 g/mol |
| Appearance | colorless liquid |
| CAS number | [76-05-1] |
| Properties | |
| Density and phase | 1.5351 g/cm3, 20 °C |
| Solubility in water | miscible |
| Melting point | -15.4 °C; 257.75 K |
| Boiling point | 72.4 °C; 345.55 K |
| Acidity (pKa) | 0.3 |
| Viscosity | ? cP at ? °C |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | Highly corrosive |
| NFPA 704 |
1
3
1
|
| Flash point | -3 °C |
| R/S statement | R: R20 R35 R52/53 S: S9 S26 S27 S28 S45 S61 |
| RTECS number | AJ9625000 |
| Related compounds | |
| Related compounds | Acetic acid Trichloroacetic acid |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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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 100,000-fold more acidic. TFA is widely used in organic chemistry.
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[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 say 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 frequently used as a buffer in liquid chromatography for separation of organic compounds, particularly peptides and small proteins. It is a versatile solvent for NMR spectroscopy.
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.
[edit] References
- ^ Eidman, K. F.; Nichols, P. J. "Trifluoroacetic Acid" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI:10.1002/047084289
