Term: homolysis (homolytic)
https://doi.org/10.1351/goldbook.H02851

Definition:
The cleavage of a bond ('homolytic cleavage' or 'homolytic fission') so that each of the molecular fragments between which the bond is broken retains one of the bonding electrons. A unimolecular reaction involving homolysis of a bond (not forming part of a cyclic structure) in a molecular entity containing an even number of (paired) electrons results in the formation of two radicals: H02851.png It is the reverse of colligation. Homolysis is also commonly a feature of bimolecular substitution reactions (and of other reactions) involving radicals and molecules.

Related Terms:
1) bond-dissociation energy (http://doi.org/10.1351/goldbook.B00699).
2) heterolysis (http://doi.org/10.1351/goldbook.H02809).
3) unimolecular (http://doi.org/10.1351/goldbook.M03989-1).
4) colligation (http://doi.org/10.1351/goldbook.C01153).
5) bimolecular substitution reactions (http://doi.org/10.1351/goldbook.M03989-2).

Image: Not defined (https://goldbook.iupac.org/img/inline/H02851.png) 

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1122 (https://doi.org/10.1351/pac199466051077)

Citation: 'homolysis (homolytic)' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.H02851

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