An aryl radical in

organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

is a reactive intermediate and an arene compound incorporating one free radical

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

atom as part of the ring structure. As such it is the radical counterpart of the arenium ion. The parent compound is the phenyl radical .''Minireview Intermolecular Olefin Functionalisation Involving Aryl Radicals Generated from Arenediazonium Salts'' Markus R. Heinrich Chemistry - A European Journal 2008 volume 15 issue 4, pages 820 - 833 Aryl radicals are intermediates in certain organic reactions.

Synthesis

Aryl radicals can be obtained via aryl

diazonium salt Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. The parent, comp ...

s. Alternatives for these salts are certain aryl triazenes and aryl

hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly hazardous unless handled in solution as, for example, hydraz ...

s. Aryl bromides and iodides can be converted to aryl radicals via tributyltin hydride and related compounds and silyl hydrides. Aryl halides can also be converted via electrochemical cathodic reduction The

mushroom A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom. The standard for the n ...

''Stephanospora caroticolor'' is suspected to generate an aryl radical as part of its biological chemical defence mechanism.

Spectroscopy

The parent phenyl radical has been identified by electron paramagnetic resonance and UV spectroscopy.

Reactions

Aryl radicals are very reactive and are found in many different reactions. Hydrogen-atom abstraction is considered a side reaction. Several reactions of synthetic utility in which aryl radicals feature are: * Halogen transfer * reaction with electron-deficient alkenes in the Meerwein arylation * biaryl couplings * Sandmeyer reactions * addition to iminium ions * addition to

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is r ...

References

{{DEFAULTSORT:Aryl radical Free radicals