Year: 2026
Type: article
Abstract: Precise control over the presence and position of knots in polymers remains a long-standing synthetic challenge, with theory indicating broad implications for properties and function. Here we report on a topological synthon approach-extension and macrocyclization of an overhand knot-that enables the high yielding synthesis of closed-loop trefoiled polymers with narrow polydispersity and tunable topological parameters. From the same set of building blocks we prepared linear, cyclic and trefoiled topoisomers of matched chemical composition, allowing topology-property relationships to be examined directly. Low-temperature ultrahigh-vacuum scanning tunnelling microscopy resolved three conformers of trefoiled polystyrene, with high-, medium- and low-symmetry forms whose populations depend on chain length, local flexibility and solvation. Coarse‑grained Langevin dynamics reproduce these distributions and indicate that bending energy and conformational entropy govern conformer stability. Metal binding localizes the knotted region, reminiscent of protein/DNA knot translocation. The synthon also affords trefoiled poly(ethylene glycol) and trefoiled polystyrene-poly(ethylene glycol) diblock copolymers, demonstrating the generality of the approach across polymer backbones.
Source: Nature Chemistry
Institutions: East China Normal University, Shenzhen University, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, State Key Laboratory of Organometallic Chemistry, Fudan University, Shanghai Jiao Tong University, City University of Hong Kong, University of Manchester
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $12,690
Funders: Natural Science Foundation of Shanghai, National Natural Science Foundation of China, Chinese Academy of Sciences, East China Normal University, Natural Science Foundation of Chongqing, Engineering and Physical Sciences Research Council, Basic and Applied Basic Research Foundation of Guangdong Province
OpenAlex ID: W7166571668