Separation of Xylene Isomers in the Anion‐Pillared Square Grid Material SIFSIX‐1‐Cu

Abstract Xylene isomer separation is considered one of the seven separation challenges that changed the world. In addition, the high‐energy demand of xylene separation highlights the need for efficient novel adsorbents. Herein, the liquid‐phase separation potential of the anion‐pillared hybrid material SIFSIX‐1‐Cu was studied for preferential adsorption of o ‐xylene and m ‐xylene over p ‐xylene, which was inspired by a previous complexation crystallization method for separating m ‐xylene. We report detailed experimental liquid‐phase adsorption experiments, yielding selectivities of 3.0 for o ‐xylene versus p ‐xylene and 2.6 for m ‐xylene versus p ‐xylene. Our theoretical calculations thus provide a reasonable explanation that the xylene adsorption selectivity is attributed to the C−H⋅⋅⋅F interaction, and the host–guest interaction order agrees with the adsorption priority: o ‐xylene > m ‐xylene > p ‐xylene.