A Polycatenane‑Topological Covalent Organic Polymer for High‑Performance Photocatalytic H₂O₂ Production

The introduction of polycatenane junctions into dative B←N bond-linked covalent organic polymers (COPs) poses a significant synthetic challenge for the synergistic optimization of both geometric stabilization and molecular functionality. Herein, we strategically employ tritopic borate ligands bearing terminal -Br substituents, rather than their ditopic counterparts, as precursors to construct a single-crystalline COP (JNP-7) featuring polycatenane-like topological junctions. Specifically, B-centered Lewis acceptors and N-donor units initially assemble into 1D nanoribbons via dative B←N linkages. By leveraging inter-nanoribbon halogen···halogen interactions between the semi-interlocked Br-containing motifs, the architecture is further extended into 2D arrays, thereby elevating the geometric dimensionality of JNP-7. Critically, the resulting polycatenated halogen-bonded network imparts exceptional structural rigidity, and the dative B←N motifs are found to concurrently promote visible-light harvesting and facilitate charge-carrier migration. Consequently, JNP-7 enables highly efficient H₂O₂ production via both the oxygen reduction reaction (ORR) and water oxidation reaction (WOR) under ambient sunlight, operating without sacrificial agents, photosensitizers, or metal cocatalysts, and outperforming state-of-the-art covalent organic frameworks (COFs) and metal-organic frameworks (MOFs) in terms of photocatalytic activity and apparent quantum yield (AQY). By aligning molecular topology with catalytic function, this work establishes a generalizable framework for the rational development of topologically sophisticated, high-performance COP systems.