Pore Space Partitioning by Using Two C3 Ligands as a Route toward a Quaternary Metal–Organic Framework

Design and synthesis of multinary metal–organic frameworks (MOFs) are of paramount importance but challenging. Nevertheless, pore space partitioning has provided a valuable avenue to isolate ternary MOFs bearing advanced gas storage and separation properties. Herein, a rare (3,3,8)-c Fe-BQDC-BTC-TPBTC MOF was constructed by means of solvothermal reaction between iron ions, a zigzag dicarboxylate H₂BQDC ligand and another two C₃-symmetry TPBTC and H₃BTC linkers. In contrast to the frequently observed single hexagonal channel type, the acs net within Fe-BQDC-BTC-TPBTC possesses two types of hexagonal channels. One of them is capable of fitting two differently sized C₃-symmetry ligands, engendering an unusual quaternary MOF with a new partially partitioned acs 2/3-plus net eventually. Fe-BQDC-BTC-TPBTC demonstrates a complex bimodal porous system concomitant with a potential separation property toward the MTO product of ethylene and propene mixtures as verified by single gas adsorption and transient column breakthrough experiments, respectively.