Nonstoichiometric polycondensations via Stille coupling reactions are successfully used to obtain high‐molecular‐weight π‐conjugated polymers using 2,5‐bis(trimethylstannyl)thiophene and a dibromo phthalimide monomer, N‐hexyldecyl‐3,6‐dibromophthalimide (2), in excess from 1:1 to 1:10. The intramolecular Pd(0) catalyst transfer on 2 substituted at the polymer terminal occurs as suggested by the model reaction between 2‐(tributylstannyl)thiophene and an equimolar amount of N‐octyl‐3,6‐dibromophthalimide (4), and the reaction generates only the disubstituted compound and excess 4 in an almost 1:1 ratio. The effect of the structures of the ligands and monomers on the polymerization under nonstoichiometric conditions is investigated to elucidate the criteria for the successful intramolecular catalyst transfer. The combination of the imide structure and an electron‐rich ligand is important for promoting the catalyst transfer.

Diversified structure design is applied to donor−acceptor (D−A)-type conjugated polymers (CPs) to improve their mobility−stretchability properties. Most methods that are capable of improving mechanical durability without sacrificing charge transport performance...

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Fluorescence imaging in the second near‐infrared (NIR‐II) region has become one of the most powerful tools in clinical diagnosis and therapy assessment because of its high spatial resolution, rapid feedback, radiation safety, and low cost. Conjugated polymer nanoparticles (Pdots) based on donor‐acceptor (D‐A) polymers are some of the most promising fluorescent probes which have many superior characteristics, such as a high fluorescence brightness, good photostability, facile functionalization, and low cytotoxicity. While there has been tremendous progress in developing fluorescent polymers for use in the NIR‐II wavelength range, the types of monomer structures used as building blocks for NIR‐II fluorophores are still limited compared to those for organic solar cells and organic transistors. This review summarizes the NIR‐II fluorescent polymers reported in the past few decades. The donor/acceptor unit structures of the polymers are systematically classified and discussed, which will provide new insights into the logical molecular design of donor/acceptor units for the development of high‐brightness NIR‐II Pdots.