In free radical addition reactions, atoms or groups add across the double bond of an alkene through a mechanism involving free radicals—highly reactive species with unpaired electrons.
Steps in Free Radical Addition:
1.Initiation:
Free radicals are generated through the homolytic cleavage of a bond, typically induced by heat, light, or a catalyst.
For instance, the homolytic cleavage of Br₂ can produce two bromine radicals.
2.Propagation:
A radical reacts with the alkene, forming a new radical.
This newly formed radical continues the chain reaction, with addition occurring across the double bond.
3.Termination:
The reaction stops when two free radicals combine to form a stable product, thus terminating the chain reaction.