Crystal Engineering of Phenylenebis(azanetriyl))tetrabenzoate Based Metal–Organic Frameworks for Gas Storage Applications

Abstract

The metal–organic framework (MOF) Cu4(mpbatb)2 (mpbatb-4,4′,4″,4‴-(1,3-phenylenebis(azanetriyl))tetrabenzoate), also known as DUT-71 (DUT – Dresden University of Technology), was functionalized via postsynthetic cross-linking of the copper paddle wheels by linear salen derivatives and dabco (1,4-diazabicyclo[2.2.2]octane). This results in a series of porous MOFs, denoted as DUT-117(M) (M – Cu, Ni, Pd). Besides significant improvement of the framework robustness, the influence of the metal coordinated by the salen ligand on the gas adsorption capacity (hydrogen –196 °C, methane 25 °C, and carbon dioxide 25 °C) was investigated. In this series DUT-117(Ni) stands out as the best material for adsorptive methane storage with a high working capacity of 171 cm3·cm–3 between 5 and 65 bar.