Precision Synthesis of Various Low‐Bandgap Donor–Acceptor Alternating Conjugated Polymers via Living Suzuki–Miyaura Catalyst‐Transfer Polymerization

Abstract Herein, we demonstrate that living Suzuki–Miyaura catalyst‐transfer polymerization (SCTP) using a RuPhos Pd G3 precatalyst is a versatile method for the precision synthesis of various donor–acceptor alternating conjugated polymers (DA ACPs). First, the living SCTP of biaryl monomers with combinations of both medium to strong A and D were optimized to produce DA ACPs with controlled number average molecular weight ( M n ), narrow dispersity ( Ð , 1.05–1.29), and high yield (>87 %). Moreover, its expansion to controlled polymerization ( M n =9.2–40.0 kg mol −1 ) of an A 1 ‐D‐A 2 ‐D quateraryl monomer containing diketopyrrolopyrrole (DPP; strong A) was successful. The living SCTP also enabled the efficient one‐pot synthesis of various diblock and triblock copolymers. Lastly, the DA ACPs showed tunable optical band gap ( E g opt , from 1.29 to 1.77 eV) and highest occupied molecular orbital (HOMO) level (from −5.57 to −4.75 eV), while their block copolymers exhibited broad absorption ranges and promising visible light‐harvesting properties.