Organocatalyze d iodine-me diate d reversible-deactivation radical polymerization via photoinduced charge transfer complex catalysis

Photoredox-mediated reversible-deactivation radical polymerization (RDRP) is an effective approach to synthesize polymers with defined composition and architecture. Current photoinduced RDRP primarily depends on outer-sphere electron transfer or homolysis mechanisms. Herein, we describe an example of iodine-mediated RDRP facilitated by photoinduced charge transfer complex (CTC) catalysis. The approach uses cheap and easily accessible N-heterocyclic nitrenium salt (NHN+ <middle dot><middle dot><middle dot>I- ) as the photoactive CTC. Upon the irradiation of visible light, NHN+ <middle dot><middle dot><middle dot>I- undergoes single electron transfer to generate NHN center dot and I center dot radicals. The NHN center dot radical activates dormant Pn -I polymers via inner-sphere single electron transfer, leading to the propagating Pn center dot radical for chain growth and the I- anion for recovering the CTC, and the I center dot radical deactivates the polymerization via coupling with Pn center dot . (c) 2025 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.