Trifluoroacetic acid
3019112
225098705
2008-07-11T21:37:21Z
69.255.156.153
{{Chembox new
| Name = Trifluoroacetic acid
| ImageFileL1 = Trifluoroacetic-acid-skeletal.png
| ImageSizeL1 = 100px
| ImageFileR1 = Trifluoroacetic-acid-3D-vdW.png
| ImageSizeR1 = 120px
| ImageFile2 = Trifluoroacetic-acid-elpot.png
| ImageSize2 = 120px
| IUPACName = 1,1,1-Trifluoroethanoic acid
| OtherNames = Perfluoroacetic acid<br />Trifluoroethanoic acid<br />TFA
| Section1 = {{Chembox Identifiers
| SMILES = FC(F)(F)C(O)=O
| CASNo = 76-05-1
| RTECS = AJ9625000
}}
| Section2 = {{Chembox Properties
| Formula = C<sub>2</sub>HF<sub>3</sub>O<sub>2</sub>
| MolarMass = 114.03 g/mol
| Appearance = colorless liquid
| Density = 1.5351 g/cm<sup>3</sup>, 20 °C
| Solubility = miscible
| MeltingPt = -15.4 °C; 257.75 K
| BoilingPt = 72.4 °C; 345.55 K
| pKa = 0.3
| Viscosity =
}}
| Section7 = {{Chembox Hazards
| ExternalMSDS = [http://www.jtbaker.com/msds/englishhtml/t5525.htm External MSDS]
| MainHazards = Highly corrosive
| NFPA-H = 3
| NFPA-R = 1
| NFPA-F = 1
| FlashPt = -3 °C
| RPhrases = {{R20}} {{R35}} {{R52/53}}
| SPhrases = {{S9}} {{S26}} {{S27}} {{S28}} {{S45}} {{S61}}
}}
| Section8 = {{Chembox Related
| OtherCpds = [[Acetic acid]]<br />[[Trichloroacetic acid]]
}}
}}
'''Trifluoroacetic acid''' (TFA) is the [[chemical compound]] with the formula CF<sub>3</sub>CO<sub>2</sub>H. It is a strong [[carboxylic acid]] due to the influence of the three very [[electronegativity|electronegative]] [[fluorine]] atoms. Relative to [[acetic acid]], TFA is almost 100,000-fold more acidic. TFA is widely used in [[organic chemistry]].
==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.<ref>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}}</ref> 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 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]] (for materials stable in acid).
The derived [[acid anhydride]], [CF<sub>3</sub>C(O)]<sub>2</sub>O, is a common reagent for introducing the trifluoracetyl group.
==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 [[chemical element|elemental]] [[fluorine]] (F<sub>2</sub>) develops is a mild reaction which leaves the [[carboxylic group]] intact.
==References==
{{reflist}}
[[Category:Carboxylic acids]]
[[Category:Organofluorides]]
[[cs:Kyselina trifluoroctová]]
[[de:Trifluoressigsäure]]
[[fr:Acide trifluoroacétique]]
[[it:Acido trifluoroacetico]]
[[nl:Trifluorazijnzuur]]
[[ja:トリフルオロ酢酸]]
[[pl:Kwas trifluorooctowy]]