Dynamic Covalent Chemistry in Systematic Construction of Hydrogen-Bonded Organic Frameworks

Dynamic covalent chemistry (DCC), which enables error correction during the reversible covalent reaction process, presents an efficient approach for the design of crystalline porous materials with different topologies and pore structures. However, the application of DCC in the systematic construction of hydrogen-bonded organic frameworks (HOFs) remains largely underexplored. Herein, we introduce a DCC approach for the direct and efficient synthesis of single-crystal HOFs (termed as DCC-HOFs) with gram-scale products. Specifically, through a one-pot Schiff base reaction of pyrazole amine and aromatic aldehyde precursors affords two types of DCC-HOFs, including four [3+3] two-dimensional (2D) DCC-HOFs and two robust highly porous isoreticular [4+4] three-dimensional (3D) DCC-HOFs via pyrazole N─H···N hydrogen-bonding trimers and tetramers, respectively. Furthermore, we demonstrate that the robust, high porous 3D DCC-HOF-Si with a pore size of up to ∼0.8 nm, can serve as an efficient drug carrier. This work provides a simple solution for the scalable fabrication of functional HOFs for a wide range of applications.