Unusual porosity behavior in a new zinc-based MOF with the heptanodaltopology

Currently, the design and synthesis of metal-organic frameworks (MOFs) attract broadattention because of the interesting structural architectures and topological features which have akey role in the final behavior of their application [۱]. In order to construct porous compoundnetworks, the common strategy is employed based on the suited selection of organic linkers andmetal ions that affect the final topology of the clustered networks [۲, ۳]. In this work, to obtain anew topological structure of a zinc-۱,۳,۵-benzentricarboxylate (Zn-BTC) MOF, we choose thevarious synthetic methods in the presence of different solvents and ratios of the Zn:BTC reagents.Herein, we report the synthesis and characterization of a new Zn-BTC MOF (FUM-۱۸۱) with theheptanodal topology. The single-crystal X-ray diffraction (SCXRD) reveals that FUM-۱۸۱crystallizes in the monoclinic space group P۲۱/c. The crystal structure of FUM-۱۸۱ consists ofseven independent Zn۲+ centers, four topologically different kinds of BTC۳- groups (BTC-۱, BTC-۲, BTC-۳, and BTC-۴), four H۲O, two -OH groups, and three coordinated DMF molecules in theasymmetric unit. A precise examination of FUM-۱۸۱ demonstrates that it is a three-dimensionalnetwork with complicated and unusual pore structures. Furthermore, a detailed theoretical studyhas been carried out on the adsorption of CO۲ and CH۴ in this MOF at ۲۹۸, ۳۰۳, ۳۱۸, and ۳۳۳ Kand ۱-۵۰ bar. The theoretical gas adsorption measurement predicts that FUM-۱۸۱ has a superiorperformance in CH۴ gas adsorption compared to CO۲. It is worth mentioning, Hong et. al haverecently reported a new hexanodal zinc-BTC MOF with high CO۲ gas adsorption [۴]. Interestingly,the changing gas adsorption behavior can be observed in our reported Zn-BTC MOF by changingthe hexanodal to heptanodal topology.

کلیدواژه ها:

Zn-BTC Metal-Organic Frameworks ، The heptanodal MOF Topology ، Sorptionbehavior