Polynuclear Rare-Earth Cluster-Directed Self-Assembly of Highly Porous Zeolite-like Metal–Organic Frameworks with Methane Storage Property

Abstract

Due to their intrinsic structural features, the design and synthesis of a new type of zeolite-like metal−organic frameworks (ZMOFs) is highly desirable but challenging. Herein, solvothermal reactions between an angular dicarboxylate linker and rare-earth (RE) ions afforded two RE-MOFs, namely, Tb-ZMOF-2 and Tb-ZMOF-3, respectively. Structural analyses reveal that Tb-ZMOF-2 encompasses a novel [4 4 6 4 8 2 ] cage, while Tb-ZMOF-3 contains nonanuclear (i.e., D6R) and hexanuclear (i.e., D4R) RE clusters simultaneously, subsequently resulting in two new zeolitic topologies. Thanks to its high surface area and pore volume, Tb-ZMOF-2 demonstrates considerably high gravimetric and volumetric methane storage working capacities.

Fluoro-bridged rare-earth metal–organic frameworks

“…5) was found to form nonaclusters, as well. 68,69 The carboxylate groups in the linkers are not linear, but rather at an angle of θ ≈ 145°, giving a bent geometry. The RE (Y/Yb) resulted in a zeolite-like MOF (ZMOF) with gme topology.…”

A (4,6)-c copper–organic framework constructed from triazole-inserted dicarboxylate linker with CO2 selective adsorption

“…24–29 Recently, our group has employed a triazole-inserted dicarboxylate ligand of 4,4′-(4 H -1,2,4-triazole-3,5-diyl) dibenzoic acid (TZDB) to successfully prepare two hydrolytically stable mesoporous zirconium–organic frameworks 30 and initiate highly porous rare-earth (RE) zeolite-like MOFs for methane storage thanks to the occurrence of nonanuclear RE clusters associated with D6R secondary building units (SBUs). 31,32 It was interestingly noted that the inserted triazole-functional groups played important roles to direct the angle of TZDB, but did not involve into coordination with metal ions. Moreover, although the coordination chemistry of TZDB with a few transition metal ions has been carried out, the system of copper( ii )-TZDB was rare investigated yet.…”