Structure-directing role of immobilized polyoxometalates in the synthesis of porphyrinic Zr-based Metal-Organic Frameworks

We evidence the structure-directing role of the PW12O403- polyoxometalate in the synthesis of porphyrinic MOFs whereby it promotes the formation of the kinetic topology. Its immobilization into the MOF is successfully achieved at high temperature yielding the kinetic MOF-525/PCN-224 phases, while prohibiting the formation of the thermodynamic MOF-545 product. A combined experimental and theoretical approach uses differential PDF and DFT calculations along with solid-state NMR to show the structural integrity of the hosted POM and its location in the vicinity of the Zr-based nodes.