Fenton reaction

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The Fenton reaction is an oxidation of organic substrates catalyzed by iron salts with hydrogen peroxide in an acidic medium. It was discovered by Henry John Horstman Fenton (1854–1929) at the end of the 19th century .

Fenton-like reactions can also take place with the participation of other low-valent metal complexes such as Cu (II), Ti (III), Cr (II) or Co (II). The Fenton reaction in biological systems as an essential source of reactive oxygen species ( reactive oxygen species seen ROS) in the cell to oxidative stress lead.

To date, neither the actually reactive species nor the mechanism has been clearly clarified and is a recurring topic in many publications and review articles. Previous results suggest the formation of a metal-H 2 O 2 - adduct close.

LFe II (sol) + H 2 O 2 → LFe II (H 2 O 2 ) + sol

Depending on the selected conditions, the adduct reacts further:

LFe II (H 2 O 2 ) → LFe III + · OH + OH -

LFe II (H 2 O 2 ) → LFe IV = O + H 2 O

LFe II (H 2 O 2 ) + RH → LFe III + · R + OH - + H 2 O

Fenton's reagent

Fenton's reagent is a sulfuric acid mixture of an iron salt, usually iron (II) sulfate FeSO 4 , and hydrogen peroxide, which is generally initially introduced before the starting material to be oxidized is added. The Fenton reaction can be carried out with this mixture. The redox potential of the hydroxyl radicals released in this reagent is only slightly below the values ​​for fluorine .

The Fenton reaction and the production of Fenton's reagent are also used on an industrial scale; in addition to synthetic applications, it is also used as a very strong oxidizing agent, for example for processing waste water and leachate from landfills.

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  • HJH Fenton: On a new reaction of tartaric acid . In: Chem News . tape 33 , 1876, pp. 190 .
  • HJH Fenton: Oxidation of tartaric acid in the presence of iron . In: Journal of the Chemical Society, Transactions . tape 65 , 1894, pp. 899-910 , doi : 10.1039 / CT8946500899 .

Individual evidence

  1. ↑ Marian Valko, Klaudia Jomova, Christopher J. Rhodes, Kamil Kuča, Kamil Musílek: Redox- and non-redox-metal-induced formation of free radicals and their role in human disease . In: Archives of Toxicology . tape 90 , no. 1 , January 2016, ISSN  0340-5761 , p. 1-37 , doi : 10.1007 / s00204-015-1579-5 .