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The synthesis of ionic olefin linked three-dimensional covalent organic frameworks (3D COFs) is greatly challenging given the hardness of the formation of stable carbon-carbon double bonds (–C = C–). Herein, we report a general strategy for designing porous positively charged sp2 carbon-linked 3D COFs through the Aldol condensation promoted by quaternization. The obtained 3D COFs, namely TFPM-PZI and TAPM-PZI, showed impressive chemical stability. Furthermore, the positively charged frameworks with regular porosity endow 3D ionic COFs with selective capture radioactive ReO4−/TcO4− and great removal efficiency in simulated Hanford waste. This research not only broadens the category of 3D COFs but also promotes the application of COFs as efficient functional materials. The synthesis of ionic olefin linked threedimensional covalent organic frameworks (3D COFs) is challenging because of the difficulties in forming stable carbon-carbon double bonds. Here, the authors report a general synthesis of an ionic sp2 carbon linked COFs and demonstrate selective capture of ReO4− ions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluorine-functionalized cationic polymer network (TFTA-BPD) for efficient extraction of ReO 4 −. • TFTA-BPD for high-performance ReO 4 − removal through halogen bonding and hydrophobic interactions. • TFTA-BPD exhibits high capacity, fast kinetics, and excellent selectivity for ReO 4 −. • This work provide unconventional concepts and emerging strategies for constructing high-performance sorbents for radionuclides. Efficient removal of 99TcO 4 − from strongly acidic and alkaline nuclear wastewater is essential due to environmental protection and nuclear fuel cycle issues associated with the nuclear industry. However, the combined features of anion exchange materials with decent acid/base stability, high capacity, and high selectivity toward ReO 4 −/99TcO 4 − have not yet been achieved. Here, we explore a new strategy to overcome the aforementioned challenges by pre-organizing pyridinium-based cationic polymer network (TFTA-BPD) with sigma-holes and strongly hydrophobic fluorine atoms, which can effectively form strong halogen bonding and enhance hydrophobic interactions for selective ReO 4 −/99TcO 4 − binding. This emerging strategy not only significantly enhances the stability of the adsorbent, but also remarkably strengthens the specific affinity toward ReO 4 −/99TcO 4 − due to the synergistic effect of halogen bonding and hydrophobic interactions, compared to reported cationic polymer networks. More importantly, our TFTA-BPD exhibit fast removal kinetics, high capacity, excellent removal selectivity, and encouraging reusability, enabling efficient removal of ReO 4 − from simulated low activity waste (LAW) at Hanford and high-level waste (HLW) at the Savannah River Site in both dynamic column separation and batch experiments. Experimental and computational results indicate that the halogen-functionalized TFTA-BPD can regulate the electron distribution of adjacent N atoms and enhance charge separation through the halogen electron traction effect. This work demonstrates the enormous potential of halogen bonding and hydrophobic interactions in synergistically enhancing ReO 4 −/99TcO 4 − binding and paves the way for constructing high-performance adsorbents for HLW and LAW treatment. [ABSTRACT FROM AUTHOR]