activated monomer

https://doi.org/10.1351/goldbook.08936
Reactive species generated reversibly from a monomer.
Note: Most frequently, the activated monomer is an anionic or cationic species.
Examples: Deprotonated lactam, a protonated cyclic ether, and a Lewis acid coordinated lactone.
Source:
PAC, 2022, 94, 1093. (Terminology for chain polymerization (IUPAC Recommendations 2021)) on page 1114 [Terms] [Paper]