Trichloroacetic acid

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Trichloroacetic acid
Identifiers
CAS number 76-03-9 YesY
KEGG C11150 YesY
ChEMBL CHEMBL14053
RTECS number AJ7875000
Jmol-3D images Image 1
Properties
Molecular formula C2HCl3O2
Molar mass 163.39 g mol−1
Appearance White solid
Density 1.63 g/cm³
Melting point

57-58 °C, 330-331 K, 135-136 °F ([1])

Boiling point

197 °C, 470 K, 387 °F ([1])

Solubility in water Soluble in 0.1 parts[1]
Acidity (pKa) 0.66[2]
Structure
Dipole moment 3.23 D
Hazards
EU classification Corrosive (C)
Dangerous for
the environment (N)
R-phrases R35, R50/53
S-phrases (S1/2), S26, S36/37/39,
S45, S60, S61
NFPA 704
NFPA 704.svg
1
3
0
LD50 5000 mg/kg orally in rats[1]
Related compounds
Related chloroacetic acids Chloroacetic acid
Dichloroacetic acid
Related compounds Acetic acid
Trifluoroacetic acid
Tribromoacetic acid
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Trichloroacetic acid (TCA; also known as trichloroethanoic acid) is an analogue of acetic acid in which the three hydrogen atoms of the methyl group have all been replaced by chlorine atoms.

It is prepared by the reaction of chlorine with acetic acid in the presence of a suitable catalyst.

CH
3
COOH
+ 3Cl
2
CCl
3
COOH
+3HCl

It is widely used in biochemistry for the precipitation of macromolecules, such as proteins, DNA, and RNA. Its sodium salt is used as a weedkiller. Solutions containing trichloroacetic acid as an ingredient are used for cosmetic treatments, such as chemical peels, tattoo removal, and the treatment of warts, including genital warts. It can kill normal cells as well. It is considered safe for use for this purpose during pregnancy.[3]

Salts of trichloroacetic acid are called trichloroacetates. Reduction of trichloroacetic acid results in dichloroacetic acid, a pharmacologically active compound that shows promise for the treatment of cancer.[4]

Contents

History[edit]

The discovery of trichloroacetic acid by Jean-Baptiste Dumas in 1839 delivered a striking example to the slowly evolving theory of organic radicals and valences.[5] The theory was contrary to the beliefs of Jöns Jakob Berzelius, starting a long dispute between Dumas and Berzelius.[6]

See also[edit]

References[edit]

External links[edit]