Scheme 2. Proposed mechanism of photo-RAFT polymerization catalyzed by ZnPcS₄⁻via three pathways.^a Note: ^a(A) PET-RAFT polymerization via an oxidative quenching pathway (OQP) and (B) a reductive quenching pathway (RQP). (C) Photo-RAFT polymerization via an oxygen-mediated photoinitiation (O-PI) system. Values indicate the Gibbs free energy change (ΔG) of electron transfer reactions in three pathways calculated by DFT (coordinates and energies of PC, RAFT agent, TEOA, and O₂ were shown in ESI†).