The Polymer Society of Korea

전우진 (서울대학교)

권민상 (서울대학교)

Cyanoarene-based photocatalysts (PCs) are widely used in photo-mediated transformations but show limited efficiency in photoinduced organocatalyzed ATRP (O-ATRP). We identify that this limitation arises from preferential formation of [PC^•+…Br^-] complexes, which promotes back electron transfer (BET) and bromine-radical side reactions. To overcome this, we developed a new cyanoarene-based PC, 4DMDP-IPN, by introducing strongly electron-donating groups at the donor units. This design suppresses complex formation and mitigates BET, resulting in enhanced O-ATRP performance. Using 4DMDP-IPN, methacrylates were polymerized with high conversion, narrow dispersity, and excellent chain-end fidelity at an ultra-low PC loading of 5 ppm, eliminating the need for catalyst removal. Controlled polymerization of methyl acrylate was also achieved. This work establishes a new design strategy for efficient photocatalysts in O-ATRP.