Enabling Controlled Synthesis of Poly(1,3-dioxolane) by Anion-Binding Catalytic Cationic Ring-Opening Polymerization

Poly(1,3-dioxolane) (PDXL) is a promising chemically recyclable thermoplastic material with abundant monomer availability and excellent physical properties, yet its widespread commercial application has been hindered by synthetic challenges, particularly in controlling molecular weights and chain-end fidelities. Here, we introduce an anion-binding catalytic cationic ring-opening polymerization (CROP) strategy to enable controlled synthesis of PDXL under mild conditions, by strategically utilizing a selenocyclodiphosph(V)azane catalyst and commercial Me₃SiX (X = I or OTf) initiators. The polymerization operates via a noncovalent anion-binding principle to tame the reversible-deactivation CROP process. Notably, the Me₃SiX initiator serves not only to initiate polymerization but also as a "mask" for the α-chain end, which is cleanly converted to a hydroxyl group upon quenching to ensure telechelic fidelity. This design further allows on-demand modulation of transient concentration of cationic species through counteranion engineering: using the low nucleofugality of I^- minimizes competitive cyclization and ensures precise synthesis of low-molecular-weight (MW) α,ω-dihydroxy telechelic PDXL (4.2-24.4 kDa), whereas selecting the highly nucleofugal OTf^- coupled with a proton trap facilitates rapid propagation to high-MW PDXL (up to 562.0 kDa).