Heteroporous 2D Covalent Organic Frameworks With Functional Differentiated Crown‐Amino Pores Constructed by Node Engineering for Gold Recovery

ABSTRACT Based on network chemistry, diverse topological structures and synthetic building blocks provide multifaceted combinations for the construction of two‐dimensional covalent organic frameworks (2D COFs). Herein, we employ the hcb topology as a template, replacing the conventional C 3 and C 2 configurations with a combination of C 6 and C 2V structures, thereby reshaping the chain connection into a 1D ribbon connection. The crown‐amine structure (C 2 N) pores unique to the resulting COF‐N6 and COF‐N8, alongside the original uniform pores, achieve functional differentiation in adsorption and mass transfer. Based on an appropriate size of crown amine, COF‐N8 achieved a maximum adsorption capacity of 2577 mg/g and an adsorption equilibrium time within 20 min for AuCl 4 − . Furthermore, theoretical calculations demonstrate that the crown amine in COF‐N8 exhibits strong coordination capabilities toward Au 3+ , alongside reductive properties. This work employs node engineering to construct heteroporous 2D COFs incorporating crown‐amine structures, providing a generic strategy for differentiating pore functions.