Trifluoroacetic acid

Trifluoroacetic acid
Names
	Preferred IUPAC name Trifluoroacetic acid
	Other names 2,2,2-Trifluoroacetic acid; 2,2,2-Trifluoroethanoic acid; Perfluoroacetic acid; Trifluoroethanoic acid; TFA
Identifiers
CAS Number	76-05-1 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	742035
ChEBI	CHEBI:45892 ;
ChEMBL	ChEMBL506259 ;
ChemSpider	10239201 ;
ECHA InfoCard	100.000.846
Gmelin Reference	2729
PubChem CID	6422;
RTECS number	AJ9625000;
UNII	E5R8Z4G708 ;
CompTox Dashboard (EPA)	DTXSID00881311, DTXSID00893893 DTXSID9041578, DTXSID00881311, DTXSID00893893 ;
	InChI InChI=1S/C2HF3O2/c3-2(4,5)1(6)7/h(H,6,7) Key: DTQVDTLACAAQTR-UHFFFAOYSA-N ; InChI=1/C2HF3O2/c3-2(4,5)1(6)7/h(H,6,7) Key: DTQVDTLACAAQTR-UHFFFAOYAP;
	SMILES FC(F)(F)C(=O)O;
Properties
Chemical formula	C2HF3O2
Molar mass	114.023 g·mol−1
Appearance	colorless liquid
Odor	Pungent/Vinegar
Density	1.489 g/cm3, 20 °C
Melting point	−15.4 °C (4.3 °F; 257.8 K)
Boiling point	72.4 °C (162.3 °F; 345.5 K)
Solubility in water	miscible
Vapor pressure	0.0117 bar (1.17 kPa) at 20 °C
Acidity (pKa)	0.52
Conjugate base	trifluoroacetate
Magnetic susceptibility (χ)	-43.3·10−6 cm3/mol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Highly corrosive
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314, H332, H412
Precautionary statements	P260, P261, P264, P271, P273, P280, P301+P330+P331, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P363, P405, P501
NFPA 704 (fire diamond)	3 1 1
Safety data sheet (SDS)	External MSDS
Related compounds
Related perfluorinated acids	Heptafluorobutyric acid; Perfluorooctanoic acid; Perfluorononanoic acid
Related compounds	Acetic acid; Trichloroacetic acid
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Trifluoroacetic acid (TFA) is a synthetic organofluorine compound with the chemical formula CF₃CO₂H. It is a haloacetic acid, with all three of the acetyl group's hydrogen atoms replaced by fluorine atoms. It is a colorless liquid with a vinegar-like odor. TFA is a stronger acid than acetic acid, having an acid ionisation constant, K_a, that is approximately 34,000 times higher,^[3] as the highly electronegative fluorine atoms and consequent electron-withdrawing nature of the trifluoromethyl group weakens the oxygen-hydrogen bond (allowing for greater acidity) and stabilises the anionic conjugate base. TFA is commonly used in organic chemistry for various purposes.

^ Kreglewski, A. (1962). "Trifluoroacetic acid". Welcome to the NIST WebBook. 10 (11–12): 629–633. Retrieved 1 March 2020.
^ W. M. Haynes.; David R. Lide; Thomas J. Bruno, eds. (2016–2017). CRC Handbook of Chemistry and Physics. CRC Press. pp. 954–963. ISBN 978-1-4987-5429-3.
^ Note: Calculated from the ratio of the K_a values for TFA (pK_a = 0.23) and acetic acid (pK_a = 4.76)

[Welcome_to_the_NIST_WebBook-1] Kreglewski, A. (1962). "Trifluoroacetic acid". Welcome to the NIST WebBook. 10 (11–12): 629–633. Retrieved 1 March 2020.

[2] W. M. Haynes.; David R. Lide; Thomas J. Bruno, eds. (2016–2017). CRC Handbook of Chemistry and Physics. CRC Press. pp. 954–963. ISBN 978-1-4987-5429-3.

[3] Note: Calculated from the ratio of the K_a values for TFA (pK_a = 0.23) and acetic acid (pK_a = 4.76)

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