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Quick Reference
Formula / Notation
A-B → A• + B• (radical cleavage)
Also Known As
Homolysis, radical cleavage, symmetric bond cleavage, free radical generation
What is Homolytic Cleavage?
The breaking of a covalent bond in which each atom takes one of the shared electrons, producing two neutral radicals. This type of bond cleavage occurs in radical reactions, including free radical halogenation of alkanes and combustion processes.
Formula & Notation
A-B → A• + B• (radical cleavage)
Other Names / Synonyms: Homolysis, radical cleavage, symmetric bond cleavage, free radical generation
Properties & Characteristics
Homolytic cleavage (homolysis) is the breaking of a covalent bond in which each fragment retains one electron, producing two radicals. It occurs preferentially when bond energies are moderate, radical stability is high (tertiary, allylic, benzylic), or when energy is supplied as heat or light (photolysis). Homolysis is favoured in low-polarity media and at high temperatures. Contrast with heterolytic cleavage, which produces ions.
Uses & Applications
Homolytic cleavage initiates radical chain reactions: combustion, radical halogenation of alkanes (Cl₂ + hν → 2Cl•), polymerisation (peroxide initiators undergo homolysis), and industrial processes like steam cracking. In biology, homolytic cleavage of O-O bonds in peroxides generates reactive oxygen species (ROS).
Safety Information
Homolytic reactions can be self-sustaining chain reactions. Peroxides (which readily undergo homolysis) are shock-sensitive and can explode. Organic peroxides must be stored at low temperature, away from reducing agents, and used before expiry. Radical reactions in flammable solvents must be conducted away from ignition sources.
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
SynonymsHomolysis, radical cleavage, symmetric bond cleavage, free radical generation
Frequently Asked Questions
The breaking of a covalent bond in which each atom takes one of the shared electrons, producing two neutral radicals. This type of bond cleavage occurs in radical reactions, including free radical halogenation of alkanes and combustion processes.
Homolytic cleavage initiates radical chain reactions: combustion, radical halogenation of alkanes (Cl₂ + hν → 2Cl•), polymerisation (peroxide initiators undergo homolysis), and industrial processes like steam cracking. In biology, homolytic cleavage of O-O bonds in peroxides generates reactive oxyge…
Homolytic reactions can be self-sustaining chain reactions. Peroxides (which readily undergo homolysis) are shock-sensitive and can explode. Organic peroxides must be stored at low temperature, away from reducing agents, and used before expiry. Radical reactions in flammable solvents must be conduct…
The formula or notation for Homolytic Cleavage is: A-B → A• + B• (radical cleavage)
