Nitrogen-rich conjugated macrocycles: Synthesis, conductivity, and application in electrochemical CO2 capture

Here we report a series of nitrogen-rich conjugated macrocycles that mimic the structure and function of semiconducting 2D metal–organic and covalent organic frameworks while providing greater solution processability and surface tunability. Using a new tetraaminotriphenylene building block that is compatible with both coordination chemistry and dynamic covalent chemistry reactions, we have synthesized two distinct macrocyclic cores containing Ni–N and phenazine-based linkages, respectively. The fully conjugated macrocycle cores support strong interlayer stacking, accessible nanochannels, and out-of-plane charge transport, with pressed pellet conductivities of 10–3 S/cm observed for the nickel variants. Finally, using electrochemically mediated CO2 capture as an example, we illustrate how phenazine macrocycles dramatically improve electrical contact and active site electrochemical accessibility relative to bulk framework powders. Together, these results highlight how simple macrocycles can enable new synthetic directions as well as new applications by combining the properties of crystalline porous frameworks, the processability of nanomaterials, and the precision of molecular synthesis.