Regenerable-Catalyst-Aided, Opened to Air and Sunlight-Driven "CuAAC&ATRP" Concurrent Reaction for Sequence-Controlled Copolymer

An ideal stimuli-responsive controlled/living radical polymerization should have the ability to manipulate the reaction through spatiotemporal "on/off" controls, achieving the polymerization under fully open conditions and allowing for precise control over macromolecular architecture with defined molecular weights and monomer sequence. In this contribution, the photo (sunlight)-induced electron transfer atom transfer radical-polymerization (PET-ATRP) can be realized to be reversibly activated and deactivated under fully open conditions utilizing one-component copper(II) thioxanthone carboxylate as multifunctional photocatalyst and oxygen scavenger. The polymerization behaviors are investigated, presenting controlled features with first-order kinetics and linear relationships between molecular weights and monomer conversions. More importantly, "CuAAC&ATRP" concurrent reaction combining PET-ATRP, photodriven deoxygenation, and photoactivated CuAAC click reaction is successfully employed to synthesize the sequence-defined multiblock functional copolymers, in which the iterative monomer additions can be easily manipulated under fully open conditions.