Isoreticular Metal–Organic Frameworks Pillared by Monovalent Anions

Three isoreticular anion pillared metal–organic frameworks were synthesized using CuX2 (X = BF4–, ClO4–, NO3–) salts and the 1,1′-(2-(trifluoromethyl)-1,4-phenylene)bis(1H-imidazole) ligand (bibCF3). Single-crystal X-ray diffraction reveals that these peculiar materials, of the general formula [Cu(bibCF3)2X]·X, feature bidentate monovalent anions acting as pillars between square layers designed by metal ions and organic linkers and extraframework anions located in the channel-like pores. The materials display remarkable thermal and chemical stability and promising CO2 adsorption performance, dependent on the nature of the anion.