A quinone (or benzoquinone) is either one of the two isomers of cyclohexadienedione or a derivative thereof. Quinones are not aromatic, but are dienes. The carbonyl groups are ketone-like. Benzoquinone exists in either of two isomers with the chemical formula C₆H₄O₂. Ortho-Benzoquinone is the 1,2-dione, whereas para-quinone, or parabenzoquinone, is the 1,4-dione. Parabenzoquinone is the oxidized form of hydroquinone, and ortho-benzoquinone is the oxidized form of catechol (1,2-dihydroxybenzene). For example, an acidic Potassium iodide solution reduces a solution of benzoquinone to hydroquinone, which is oxidized back with a solution of silver nitrate. Ketone group A ketone is either the functional group characterized by a carbonyl group linked to two other carbon atoms or a chemical compound that contains this functional group. ... In chemistry, isomers are molecules with the same chemical formula and often with the same kinds of bonds between atoms, but in which the atoms are arranged differently. ... 1,4-Benzoquinone, also cyclohexa-2,5-diene-1,4-dione, is a ketone, with formula C6H4O2. ... Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. ... R-phrases , , , , , S-phrases , , , Flash point 165 °C RTECS number MX3500000 Supplementary data page Structure and properties n, εr, etc. ... Catechol, also benzene-1,2-diol, is a phenol, with formula C6H4(OH)2. ... For alternative meanings see acid (disambiguation). ... Potassium iodide is a white crystalline salt with chemical formula KI, used in photography and radiation treatment. ... R-phrases , S-phrases , , , , Flash point non-flammable Supplementary data page Structure and properties n, εr, etc. ...

orthobenzoquinone

parabenzoquinone

The word quinone refers to the entire class of cyclohexadienediones. Chemical structure of orthobenzoquinone (generated at Wikisophia. ... Chemical structure of parabenzoquinone (generated at Wikisophia. ...

Biochemistry

Quinone is a common constituent of biologically relevant molecules (e.g. Vitamin K1 is phylloquinone). Others serve as electron acceptors in electron transport chains such as those in Photosystems I & II of photosynthesis, and aerobic respiration. A natural example of quinones as oxidizing agents is the spray of bombardier beetles. Hydroquinone is reacted with hydrogen peroxide to produce a fiery blast of steam, a strong deterrent in the animal world. Quinones can be partially reduced to quinols. Vitamin K denotes a group of 2-methilo-naphthoquinone derivatives. ... REDIRECT [[In the process of photosynthesis, light is absorbed by a photosystem (ancient Greek: phos = light and systema = assembly) to begin an energy-producing reaction. ... The leaf is the primary site of photosynthesis in plants. ... This article or section should be merged with aerobic metabolism. ... European Union Chemical hazard symbol for oxidizing agents Dangerous goods label for oxidising agents An oxidizing agent (also called an oxidant or oxidizer) is referred to as A chemical compound that readily transfers oxygen atoms or A substance that gains electrons in a redox chemical reaction. ... Tribes Brachinini Paussini Ozaenini Metriini Bombardier beetles are ground beetles (Carabidae) in the tribes Brachinini, Paussini, Ozaenini, or Metriini - more than 500 species altogether - that are most notable for the defense mechanism that gives them their name: They can fire a mixture of chemicals from special glands in their posterior. ... Hydrogen peroxide (H2O2) is a very pale blue liquid which appears colourless in a dilute solution, slightly more viscous than water. ...

Organic chemistry

Benzoquinone is used in organic chemistry as an oxidizing agent. Even stronger agents exist such as 2,3,5,6-tetrachloro-parabenzoquinone or p-chloranil and 2,3-dicyano-5,6-dichloro-parabenzoquinone or DDQ for short [1]. Organic chemistry is a specific discipline within the subject of chemistry. ... Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. ...

See also

• 1,4-Benzoquinone

1,4-Benzoquinone, also cyclohexa-2,5-diene-1,4-dione, is a ketone, with formula C6H4O2. ...

External links

• Redox system Benzoquinone / Hydroquinone Website

• Links to external chemical sources.