Perfluorosulfonic acids

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Perfluorooctanesulfonic acid Perfluorooctanesulfonic acid.svg
Perfluorooctanesulfonic acid

Perfluorosulfonic acids (PFSAs) are chemical compounds of the formula CnF(2n+1)SO3H and thus belong to the family of perfluorinated and polyfluorinated alkyl compounds (PFASs). The simplest example of a perfluorosulfonic acid is the trifluoromethanesulfonic acid. Perfluorosulfonic acids with six or more perfluorinated carbon atoms, i.e. from perfluorohexanesulfonic acid onwards, are referred to as long-chain. [1]

Contents

Trifluoromethanesulfonic acid Triflic-acid Structural Formula V1.svg
Trifluoromethanesulfonic acid

Properties

Perfluorosulfonic acids are organofluoroanalogues of conventional alkanesulfonic acids, but they are several pKA units stronger (and are therefore strong acids). Their perfluoroalkyl chain has a highly hydrophobic character.

Use

Perfluorooctanesulfonic acid, for example, has been used in hard chromium plating. Since the early 2000's 6:2 fluorotelomersulfonic acid has been used as a replacement for perfluorooctanesulfonic acid. [2]

Regulation

Perfluorooctanesulfonic acid was included in Annex B of the Stockholm Convention in 2009 and subsequently in the EU POPs Regulation. [3]

Perfluorohexanesulfonic acid was included in Annex A of the Stockholm Convention in 2022. [4]

Examples

NameAbbreviation Structural formula Molecular weight (g/mol) CAS No.
Perfluoropropanesulfonic acid PFPrSC3F7SO3H250.09423-41-6
Perfluorobutanesulfonic acid PFBSC4F9SO3H300.10375-73-5
Perfluoropentanesulfonic acid PFPSC5F11SO3H350.112706-91-4
Perfluorohexanesulfonic acid PFHxSC6F13SO3H400.12355-46-4
Perfluoroheptanesulfonic acid PFHpSC7F15SO3H450.12375-92-8
Perfluorooctanesulfonic acid PFOSC8F17SO3H500.131763-23-1
Perfluorononanesulfonic acid PFNSC9F19SO3H550.1468259-12-1
Perfluorodecanesulfonic acid PFDSC10F21SO3H600.15335-77-3

See also

Literature

References

  1. "Terminology | FluoroCouncil".
  2. Bohannon, Meredith E; Narizzano, Allison M; Guigni, Blas A; East, Andrew G; Quinn, Michael J (2023). "Next-generation PFAS 6:2 fluorotelomer sulfonate reduces plaque formation in exposed white-footed mice". Toxicological Sciences. 192 (1): 97–105. doi:10.1093/toxsci/kfad006.
  3. Regulation (EU) 2019/1021 of the European Parliament and of the Council of 20 June 2019 on persistent organic pollutants
  4. "UN experts recommend elimination of additional hazardous chemicals to protect human health and the environment".