Two Comparable Isostructural Microporous Metal–Organic Frameworks: Better Luminescent Sensor and Higher Adsorption Selectivity for the Fluorine‐Decorated Framework

Two isostructural 3D metal–organic frameworks (MOFs), {[Zn 3 (tzba) 3 (dabco)] · 5DMF · 3H 2 O} ( 1 ) and {[Zn 3 (F‐tzba) 3 (dabco)] · 5DMA · 3H 2 O} ( 2 ) [tzba = 4‐(1 H ‐tetrazol‐5‐yl) benzolate, F‐tzba = 2‐fluoro‐4‐(1 H ‐tetrazol‐5‐yl) benzolate, dabco = triethylenediamine], were solvothermally synthesized from a tetrazolate–carboxylate bifunctional linker and a diamine ligand. The framework contains an uncommon metal–tetrazolate–carboxylate linear trinuclear Zn 3 (ttaz) 3 (COO) 3 (ttaz = tetrazolyl) cluster, which serves as an eight‐connected node to afford a 3D porous network. Both 1 and 2 show strong photoluminescence and selective luminescent quenching for Cu 2+ ions and nitrobenzene relative to that shown by other metal ions (e.g., Na + , K + , Mg 2+ , Ca 2+ , Mn 2+ , Co 2+ , Ni 2+ , Cd 2+ , and Pb 2+ ) and organic solvents (e.g., methanol, ethanol, acetonitrile, n ‐propanol, 2‐propanol, ethyl acetate, toluene, dichloromethane, N , N′ ‐dimethylformamide, and N ‐methylpyrrolidone). It is interesting to find that relative to 1 , 2 decorated with F atoms exhibits more efficient luminescent sensing for these two guests. Furthermore, 2 also adsorbs more CO 2 and has higher CO 2 /CH 4 adsorption selectivities than 1 under the same conditions, which can be ascribed to the CO 2 ‐philic F sites in the pores of 2 . These advantages make 2 a promising material in both luminescent sensors and CO 2 separation from a CO 2 /CH 4 mixture.