Harber-Weiss reaction
Encyclopedia
The Haber-Weiss reaction generates •OH (hydroxyl radicals
) from H2O2 (hydrogen peroxide
) and superoxide
(•O2-). This reaction can occur in cells
and is therefore a possible source for oxidative stress
. The reaction is very slow, but is catalyzed by iron. The first step of the catalytic cycle
involves reduction of ferric ion to ferrous:
The second step is the Fenton reaction
:
Net reaction:
The reaction is named after Fritz Haber
and his student Joseph Joshua Weiss
.
Hydroxyl
A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
) from H2O2 (hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
) and superoxide
Superoxide
A superoxide, also known by the obsolete name hyperoxide, is a compound that possesses the superoxide anion with the chemical formula O2−. The systematic name of the anion is dioxide. It is important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature...
(•O2-). This reaction can occur in cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
and is therefore a possible source for oxidative stress
Oxidative stress
Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
. The reaction is very slow, but is catalyzed by iron. The first step of the catalytic cycle
Catalytic cycle
A catalytic cycle in chemistry is a term for a multistep reaction mechanism that involves a catalyst . The catalytic cycle is the main method for describing the role of catalysts in biochemistry, organometallic chemistry, materials science, etc. Often such cycles show the conversion of a...
involves reduction of ferric ion to ferrous:
- Fe3+ + •O2− → Fe2+ + O2
The second step is the Fenton reaction
Fenton's reagent
Fenton's reagent is a solution of hydrogen peroxide and an iron catalyst that is used to oxidize contaminants or waste waters. Fenton's reagent can be used to destroy organic compounds such as trichloroethylene and tetrachloroethylene ....
:
- Fe2+ + H2O2 → Fe3+ + OH− + •OH
Net reaction:
- •O2- + H2O2 → •OH + OH- + O2
The reaction is named after Fritz Haber
Fritz Haber
Fritz Haber was a German chemist, who received the Nobel Prize in Chemistry in 1918 for his development for synthesizing ammonia, important for fertilizers and explosives. Haber, along with Max Born, proposed the Born–Haber cycle as a method for evaluating the lattice energy of an ionic solid...
and his student Joseph Joshua Weiss
Joseph Joshua Weiss
Joseph Joshua Weiss was a Jewish-Austrian chemist and Professor at the Newcastle University. He was a pioneer in the field of radiation and photochemistry...
.