backbiting

A rearrangement that can occur in some polymerization reactions involving free radicals. A radical that has an unpaired electron at the end of the chain changes into a radical with the unpaired electron elsewhere along the chain, the new radical being more stable than the one from which it originates. For ex­ample, the radical RCH₂CH₂CH₂CH₂CH₂CH₂·  may change into RCH₂CH·CH₂CH₂CH₂CH₃

The rearrangement is equivalent to a hydrogen atom being transferred within the molecule. The new un­paired electron initiates further polymerization, with the produc­tion of polymers with butyl (CH₃CH₂CH₂CH₂-) side chains.