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

Abstract

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.