One-Step Precise Synthesis of Sequence-Defined ABCB-Type Se-Containing Polymers with Tunable Properties

The development of synthetic polymers with precisely tailored monomer sequences represents a critical yet challenging frontier in polymer science. In this study, we present a modular strategy for the synthesis of ABCB-type periodic polymers through the first reported step-polymerization of diols (or diamines), diacrylates, and a Se-containing lactone. This approach leverages exclusive chemoselectivity to achieve precise monomer placement within the polymer chain, enabling the incorporation of selenoether and ester (or amide) groups in well-defined repeating units. The method exhibits broad monomer compatibility, yielding 72 new polymers with precisely controlled sequences. The resulting polymer library demonstrates extensively tunable properties, including glass transition temperatures ranging from −69 to 21 °C, melting temperatures from 1 to 132 °C, polyethylene-like mechanical characteristics, chemical recyclability, and Se-donating functionality. Notably, the process is atom-economical, metal-free, and catalyst-free, utilizing readily available monomers to produce polymers with >95% yields and weight-average molecular weights up to 133.6 kDa. This work establishes a facile and versatile platform for the synthesis of sequence-controlled Se-containing polymers, offering new opportunities for advanced material design.