Two-in-One Strategy for Photoinduced Atom Transfer Radical Polymerization Using Cu(I)-Phenothiazine Integrated...

The concurrent development of innovative photocatalysts (PCs) that achieve fast reaction rates while ensuring efficient catalyst recycling remains a significant challenge for large-scale polymer production. Herein, we present a "two-in-one" strategy that combines a photoactive component with a cyclic trinuclear Cu(I)-incorporated triangular complex as the intrinsic copper source within three imine-linked covalent organic frameworks (COFs). As-synthesized photoactive Cu(I)-containing COFs demonstrated exceptional performance in aqueous photoinduced atom transfer radical polymerization (photo-ATRP), achieving a record-breaking turnover number (TON) of 1640 and turnover frequency (TOF) of 82 min^-1, while maintaining narrow polymer dispersity of 1.20. Such performance surpasses previously reported heterogeneous PCs designed for photo-ATRP. Notably, the COF-encapsulated "two-in-one" catalytic design endows the system with remarkable operational stability and near-quantitative catalyst recovery. More importantly, such new COFs demonstrate outstanding process compatibility, enabling scalable production of well-defined block copolymers in a single microreactor, without intermediate purification.