Fused aromatic networks with the different spatial arrangement of structural units

Abstract

Fused aromatic networks (FANs) are a new generation of porous organic networks (PONs), which are thermodynamic products. FANs are also kinetic products with low crystallinity. Nevertheless, their high physicochemical stability suggests many potential applications. This work reports three structures with their fully fused aromatic units vertically (V), horizontally (H), and three-dimensionally (3D) linked to the growth direction, forming “standing” FAN (VS-FAN), “planar” FAN (HP-FAN), and 3D-FAN, respectively. Their performance as sorbent materials was evaluated. While the VS-FAN has the fastest kinetics for CH 4 and I 2 adsorption due to the highest segmental freedom, the HP-FAN exhibits the best separation selectivity of the CH 4 /N 2 mixture due to the strongest segmental confinement. The 3D-FAN displays the highest adsorption capacity of CH 4 because of the highest specific surface area. The results suggest that the different segmental arrangements may critically affect the sorbent performance of FANs. FAN structures are vertically, horizontally, and three-dimensionally linked As sorbent materials, vertically standing FAN has the fastest adsorption kinetics Horizontally planar FAN has the highest gas separation selectivity Three-dimensionally arranged FAN shows the highest gas adsorption capacity Is there a difference in gas adsorption characteristics depending on the polymer growth direction and the monomer symmetry? Kim et al. design planar 2D, vertically standing 2D, and porous 3D fused aromatic networks (FANs) based on the monomer symmetry and show the gas adsorption and separation properties and their kinetics according to the structures.