Selective pore modulation in layered molecular crystals

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Multi-porous reticular materials, featuring various pore sizes and shapes, have gained increasing attention due to their structural properties that facilitate mass transport. However, the rational design of such materials remains challenging, particularly when selectively modulating pore sizes. Here we present a synthesis strategy that enables selective pore modulation in dual-porous layered double-walled hydrogen-bonded organic frameworks using triskele-shaped building units. We uncovered an unusual syn conformation of acylhydrazone, which forms hydrogen bonding with carboxyl groups, thereby allowing the rapid, scalable synthesis of a series of single crystals with exceptional stability, including resistance to aqua regia. Harnessing the enriched proton-hopping sites and acid robustness of the double-walled framework, we demonstrate that incorporating superacids into these dual-porous crystals effectively enhances proton conductivity, which reaches 4.25 × 10 −3 S cm −1 at 30 °C. Furthermore, we elucidate the formation mechanism of double-walled hydrogen-bonded organic frameworks via a combination of experimental and computational approaches. This work opens avenues for the tailored design of multi-porous materials with independently tunable pore architectures and functionalities.

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Crystallographic data for the structures reported in this article have been deposited at the Cambridge Crystallographic Data Centre, under deposition numbers CCDC 2561118 (DW-HOF-1a) and 2561119 (DW-HOF-2). Copies of the data can be obtained free of charge via https://www.ccdc.cam.ac.uk/structures/ . All data supporting the findings of this study are available within the paper and its Supplementary Information files. Source data are provided with this paper.

Czaja, A. U., Trukhan, N. & Müller, U. Industrial applications of metal, organic frameworks. Chem. Soc. Rev. 38 , 1284, 1293 (2009).

Zhang, Q., Gao, S. & Yu, J. Metal sites in zeolites: synthesis, characterization, and catalysis. Chem. Rev. 123 , 6039, 6106 (2023).

Wang, K., Qiao, X., Ren, H., Chen, Y. & Zhang, Z. Industrialization of covalent organic frameworks. J. Am. Chem. Soc. 147 , 8063, 8082 (2025).

Teo, W. L., Zhou, W., Qian, C. & Zhao, Y. Industrializing metal, organic frameworks: scalable synthetic means and their transformation into functional materials. Mater. Today 47 , 170, 186 (2021).

Bennett, T. D., Coudert, F.-X., James, S. L. & Cooper, A. I. The changing state of porous materials. Nat. Mater. 20 , 1179, 1187 (2021).

Yaghi, O. M. et al. Reticular synthesis and the design of new materials. Nature 423 , 705, 714 (2003).

Yaghi, O. M. Reticular chemistry, construction, properties, and precision reactions of frameworks. J. Am. Chem. Soc. 138 , 15507, 15509 (2016).

Freund, R. et al. 25 years of reticular chemistry. Angew. Chem. Int. Ed. 60 , 23946, 23974 (2021).

Zhou, H.-C., Long, J. R. & Yaghi, O. M. Introduction to metal, organic frameworks. Chem. Rev. 112 , 673, 674 (2012).

Diercks, C. S. & Yaghi, O. M. The atom, the molecule, and the covalent organic framework. Science 355 , eaal1585 (2017).

Geng, K. et al. Covalent organic frameworks: design, synthesis, and functions. Chem. Rev. 120 , 8814, 8933 (2020).

Wang, B., Lin, R.-B., Zhang, Z., Xiang, S. & Chen, B. Hydrogen-bonded organic frameworks as a tunable platform for functional materials. J. Am. Chem. Soc. 142 , 14399, 14416 (2020).

Lin, R.-B. & Chen, B. Hydrogen-bonded organic frameworks: chemistry and functions. Chem 8 , 2114, 2135 (2022).

Sasmal Himadri, S. et al. Superprotonic conductivity in flexible porous covalent organic framework membranes. Angew. Chem. Int. Ed. 57 , 10894, 10898 (2018).

Xu, H., Tao, S. & Jiang, D. Proton conduction in crystalline and porous covalent organic frameworks. Nat. Mater. 15 , 722, 726 (2016).

Jiang, Z. et al. Isotopological entanglement of a metal, organic framework and a hydrogen-bonded organic framework for proton conduction. Nat. Synth. 4 , 622, 631 (2025).

Pal, S. C., Mukherjee, D., Sahoo, R., Mondal, S. & Das, M. C. Proton-conducting hydrogen-bonded organic frameworks. ACS Energy Lett. 6 , 4431, 4453 (2021).

Yang, J. et al. Oxygen- and proton-transporting open framework ionomer for medium-temperature fuel cells. Science 385 , 1115, 1120 (2024).

Zhang, R. et al. Balancing volumetric and gravimetric capacity for hydrogen in supramolecular crystals. Nat. Chem. 16 , 1982, 1988 (2024).

Rohde, R. C. et al. High-temperature carbon dioxide capture in a porous material with terminal zinc hydride sites. Science 386 , 814, 819 (2024).

Zhou, Z. et al. Carbon dioxide capture from open air using covalent organic frameworks. Nature 635 , 96, 101 (2024).

Yin, Y. et al. Ultrahigh, surface area covalent organic frameworks for methane adsorption. Science 386 , 693, 696 (2024).

Cai, G., Yan, P., Zhang, L., Zhou, H.-C. & Jiang, H.-L. Metal, organic framework-based hierarchically porous materials: synthesis and applications. Chem. Rev. 121 , 12278, 12326 (2021).

Qian, C. & Zhao, X. Two-dimensional heteropore covalent organic frameworks: from construction to functions. Acc. Chem. Res. 58 , 1192, 1209 (2025).

Alhashmi, S. et al. Diffusion and adsorption in covalent organic frameworks (COFs) probed by nuclear magnetic resonance methods. Mater. Today Chem. 41 , 102245 (2024).

Xie, Z. et al. Stable 2D heteroporous covalent organic frameworks for efficient ionic conduction. Angew. Chem. Int. Ed. 58 , 15742, 15746 (2019).

Yin, Q. et al. Novel hierarchical meso-microporous hydrogen-bonded organic framework for selective separation of acetylene and ethylene versus methane. ACS Appl. Mater. Interfaces 11 , 17823, 17827 (2019).

Jiang, Z. et al. Filling metal, organic framework mesopores with TiO 2 for CO 2 photoreduction. Nature 586 , 549, 554 (2020).

Mondloch, J. E. et al. Vapor-phase metalation by atomic layer deposition in a metal, organic framework. J. Am. Chem. Soc. 135 , 10294, 10297 (2013).

Du, M. et al. Ligand symmetry modulation for designing a mesoporous metal, organic framework: dual reactivity to transition and lanthanide metals for enhanced functionalization. Chem. Eur. J. 21 , 9713, 9719 (2015).

Zhou, T.-Y., Xu, S.-Q., Wen, Q., Pang, Z.-F. & Zhao, X. One-step construction of two different kinds of pores in a 2D covalent organic framework. J. Am. Chem. Soc. 136 , 15885, 15888 (2014).

Tian, Y. et al. Construction of two heteropore covalent organic frameworks with Kagome lattices. CrystEngComm 19 , 4877, 4881 (2017).

Cai, S.-L. et al. An unprecedented 2D covalent organic framework with an htb net topology. Chem. Commun. 55 , 13454, 13457 (2019).

Xu, S.-Q., Zhan, T.-G., Wen, Q., Pang, Z.-F. & Zhao, X. Diversity of covalent organic frameworks (COFs): a 2D COF containing two kinds of triangular micropores of different sizes. ACS Macro Lett. 5 , 99, 102 (2016).

Tian, Y. et al. Two-dimensional dual-pore covalent organic frameworks obtained from the combination of two D 2h symmetrical building blocks. Chem. Commun. 52 , 11704, 11707 (2016).

Qian, C. et al. Toward covalent organic frameworks bearing three different kinds of pores: the strategy for construction and COF-to-COF transformation via heterogeneous linker exchange. J. Am. Chem. Soc. 139 , 6736, 6743 (2017).

Zhang, B. et al. Reticular synthesis of multinary covalent organic frameworks. J. Am. Chem. Soc. 141 , 11420, 11424 (2019).

Jiang, S.-Y. et al. Aminal-linked covalent organic frameworks through condensation of secondary amine with aldehyde. J. Am. Chem. Soc. 141 , 14981, 14986 (2019).

Férey, G. et al. A chromium terephthalate-based solid with unusually large pore volumes and surface area. Science 309 , 2040, 2042 (2005).

Kang, X. et al. Reticular synthesis of tbo topology covalent organic frameworks. J. Am. Chem. Soc. 142 , 16346, 16356 (2020).

Yu, B. et al. Single-crystalline 3D covalent organic frameworks with exceptionally high specific surface areas and gas storage capacities. J. Am. Chem. Soc. 146 , 28932, 28940 (2024).

Zhu, Y., Wan, S., Jin, Y. & Zhang, W. Desymmetrized vertex design for the synthesis of covalent organic frameworks with periodically heterogeneous pore structures. J. Am. Chem. Soc. 137 , 13772, 13775 (2015).

Koh, K., Wong-Foy, A. G. & Matzger, A. J. A crystalline mesoporous coordination copolymer with high microporosity. Angew. Chem. Int. Ed. 47 , 677, 680 (2008).

Furukawa, H. et al. Ultrahigh porosity in metal, organic frameworks. Science 329 , 424, 428 (2010).

Liang, R.-R., Xu, S.-Q., Pang, Z.-F., Qi, Q.-Y. & Zhao, X. Self-sorted pore-formation in the construction of heteropore covalent organic frameworks based on orthogonal reactions. Chem. Commun. 54 , 880, 883 (2018).

Nguyen, H. L., Gropp, C. & Yaghi, O. M. Reticulating 1D ribbons into 2D covalent organic frameworks by imine and imide linkages. J. Am. Chem. Soc. 142 , 2771, 2776 (2020).

Deng, H. et al. Large-pore apertures in a series of metal, organic frameworks. Science 336 , 1018, 1023 (2012).

Pang, Z.-F. et al. Construction of covalent organic frameworks bearing three different kinds of pores through the heterostructural mixed linker strategy. J. Am. Chem. Soc. 138 , 4710, 4713 (2016).