F

Free Radical

R•; homolytic: A-B → A• + B•; detected by ESR/EPR
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Quick Reference
Formula / NotationR•; homolytic: A-B → A• + B•; detected by ESR/EPR
Also Known AsRadical, free radical species, reactive intermediate, paramagnetic species

What is Free Radical?

A highly reactive chemical species containing one or more unpaired electrons. Free radicals are formed by homolytic cleavage of covalent bonds. They initiate chain reactions in combustion, polymerization, and biological processes. Antioxidants prevent harmful radical damage.

Formula & Notation

R•; homolytic: A-B → A• + B•; detected by ESR/EPR

Other Names / Synonyms: Radical, free radical species, reactive intermediate, paramagnetic species

Properties & Characteristics

A free radical is an atom, molecule, or ion with at least one unpaired electron. Radicals are highly reactive because unpaired electrons seek to form bonds by abstracting atoms from other molecules or by coupling with other radicals. They are detected by electron spin resonance (ESR/EPR) spectroscopy. Common radicals: Cl•, OH•, NO•, superoxide (O₂•⁻). Radicals propagate chain reactions and are key intermediates in atmospheric chemistry and combustion.

Uses & Applications

Free radicals are exploited in: radical polymerisation (production of polystyrene, PVC, polyethylene), organic synthesis (radical halogenation, radical cyclisations, Barton reaction), combustion (fuel oxidation mechanism), atmospheric chemistry (ozone depletion by Cl• radicals), and in biology (reactive oxygen species — ROS — in cell signalling and oxidative stress).

Safety Information

Industrial processes generating high concentrations of radicals (peroxide decomposition, radiation) are fire and explosion hazards. Reactive oxygen species (superoxide, hydroxyl radical) cause oxidative DNA damage and disease. Radical initiators (AIBN, peroxides) used in polymerisation are flammable and can decompose explosively if heated.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Free Radical
Formula R•; homolytic: A-B → A• + B•; detected by ESR/EPR
Index All "F" terms
Synonyms Radical, free radical species, reactive intermediate, paramagnetic species

Frequently Asked Questions

A highly reactive chemical species containing one or more unpaired electrons. Free radicals are formed by homolytic cleavage of covalent bonds. They initiate chain reactions in combustion, polymerization, and biological processes. Antioxidants prevent harmful radical damage.

More "F" Terms

2-Furoic acid C5H4O3 Faraday F = 96,485 C/mol Faraday's Law of Electrolysis m = (M × I × t) / (F × z) Faraday's Law Of Electrolysis Farnesol C15H26O Fast Neutron Fat Fatty Acids CH₃(CH₂)ₙCOOH Fermium Fm Ferric ammonium citrate C6H11FeNO7+3 Ferric hydroxide Fe(OH)3 Ferromagnetism
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Editorial standards: Chemical data is sourced from peer-reviewed literature, CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA, and IAEA. For educational purposes only — always consult official SDS documentation and qualified professionals before handling chemicals.

AllChemicals.info — The Online Chemical Glossary | https://allchemicals.info/chemical/442-free-radical

For educational purposes only. Verify all information before use.