Macrocyclic ligand-driven ion selectivity and high surface area in a 2D conductive MOF

Summary

Two-dimensional electrically conductive metal-organic frameworks (2D EC-MOFs) have emerged as promising electronic materials despite their low surface areas and limited functionalities. Herein, we exploited molecular-level design of a macrocyclic ligand, ethynylphenanthrene (EP), wherein intrinsic pockets target both complementary surface area and extra layer of functionality. With copper nodes, Cu-EP exhibits an electrical conductivity of 1.0 × 10⁻³ S/cm and a record-high surface area of 1,502 m²/g among reported 2D EC-MOFs. Moreover, the intended large intrinsic pocket (6.5 Å) demonstrates capability to host bulky electrolytes, enhancing capacitive performance. Additionally, the pockets of Cu-EP selectively host Cs⁺ over Li⁺. Our results boast rational design of large intrinsic pockets to address common limitations of 2D EC-MOFs and further contribute to diversifying their functions with redox activity and ion selectivity, promoting a new paradigm for EC-MOFs' broader utilities.