Chiral Self-Sorting Programs Polymer Network Topology and Suppresses Primary Loops

Researchers have demonstrated that homochiral self-sorting can be harnessed to suppress primary loops in end-linked polymer networks, establishing stereochemical recognition as an effective design handle to program network topology.

While stereochemistry has long exerted a strong influence over polymer structure and molecular assembly, its utilization as a design handle to regulate polymer network topology has remained unexplored. The authors developed a design principle specifically aimed at employing homochiral self-sorting to overcome this limitation and suppress primary loop formation.

To validate this topological strategy, the authors synthesized linear polymers terminated with bi-2-naphthol-based ligands designed for coordination assembly. The experimental design relied on preparing and isolating polymer ligands with specifically configured chain ends, encompassing both homochiral and heterochiral ligand terminations.

Cross-linking in this system is driven by coordination chemistry, specifically palladium(II)-mediated assembly of metal–organic cages (MOCs) with a Pd2L4 formulation.

The core operating principle of this design exploits a distinct thermodynamic preference for homochiral MOCs during coordination assembly. When linear polymers are terminated with heterochiral ligands, the thermodynamic favoring of homochiral cages enforces a pronounced bias against intramolecular cyclization.

The researchers conducted comparative evaluations between networks formed from heterochiral polymers and those assembled from homochiral polymers. Networks formed from homochiral polymers can form primary loops through MOC formation. Consequently, networks formed from heterochiral polymers exhibited lower primary loop densities than their homochiral counterparts, resulting in enhanced mechanical properties. Mechanical property comparisons of M and M–P-polyMOC networks were measured at 4 rad s−1 and 3% strain.

Beyond suppressing loop defects during initial assembly, the team discovered that the presence of sacrificial loops at low polymer concentrations enables post-assembly network topology editing. Adding functionalized free ligands enables topology editing with minimal impact on network integrity. This work establishes chiral self-sorting as a versatile approach to controlling polymer topology and provides a generalizable strategy for designing robust and functional polymer networks.

Subject of Research: Regulation of supramolecular polymer network topology through homochiral self-sorting

Article Title: Programming supramolecular polymer network topology via homochiral self-sorting

Article References: Wang, Y., Bobylev, E. O., Wang, K., Kulik, H. J., & Johnson, J. A. (2026). Programming supramolecular polymer network topology via homochiral self-sorting. Nature Chemistry. https://doi.org/10.1038/s41557-026-02282-8

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DOI: 10.1038/s41557-026-02282-8

Keywords: polymer topology, supramolecular polymers, homochiral self-sorting, metal-organic cages, stereochemistry, primary loops, intramolecular cyclization, polymer networks, Programming, supramolecular, polymer, network