D–A Conjugated Organic Polymers as Nonhomogeneous Photocatalysts for PET-RAFT Polymerization

D–A conjugated organic polymer (COP) photocatalysts are a very promising photocatalytic material because of their tunable structure at the molecular level and diverse species. D–A conjugated organic polymers composed of relatively weak donor units and strong acceptor units are more favorable for photogenerated charge migration and thus exhibit better photocatalytic activity. Herein, a series of D–A conjugated organic polymers were constructed by introducing CN-absorbing groups to the benzene ring using 1,3,5-triethynylbenzene as the donor unit and the benzene ring as the acceptor unit to catalyze the reversible addition–fragmentation chain transfer (RAFT) polymerization of methyl methacrylate under white light irradiation, and the resulting polymers had controlled molecular weight and narrow molecular weight distribution. The effect of increasing the number of CN groups on the photogenerated charge migration ability of the catalyst and the RAFT polymerization rate was investigated by both experiments and theoretical calculation to reveal the conformational relationship between the polymer structure and the photocatalytic RAFT polymerization rate. It is proved that D–A conjugated organic polymers composed of relatively weak donor units and strong acceptor units are more favorable for photogenerated charge migration and thus exhibit better photocatalytic activity.