In situ Electron Magnetic Resonance study of coordinative and structural transformations in paramagnetically doped Metal Organic Frameworks

by EMR and COMOC research teams of UGent

This project of the EMR and COMOC teams of Ghent University aims to gain insight in the catalytic activity and structural flexibility of metal-organic frameworks (MOFs). These porous network structures, built up from metal centres and organic linkers, allow tayloring structure, pore size and shape to desired functionality. Their applications in diverse fields (adsorption, catalysis, separations, ...) are currently being explored.

Elementary reaction steps during catalysis and structural transformations will be investigated on a selection of AlIII-OH-, isostructural VIV=O-MOFs, and their mixtures. Electron magnetic resonance (EMR) will be used as primary spectroscopic tool, as it provides quantitative and structural information on the metal complexes in MOFs, including their valence state and ligand structure. VIV=O EMR spectra can be detected in a wide temperature range, but in fully concentrated MOFs, they show limited resolution. Hence, EMR experiments on VIV=O-doped AlIII-OH-MOFs will also be made to monitor changes in the metal-ligand structure, during and after catalysis. The selection of MOFs includes one flexible AlIII-OH-MOF for which the isostructural VIV=O-MOF has a rigid structure, and two for which the reverse behaviour is observed. Studying VIV=O-doped AlIII-OH-MOFs as function of concentration will elucidate the relation between metal-linker interactions and flexibility.

The insights gathered in our study will contribute to a more efficient MOF design.

Perspective view of MIL-47 (VIV=O(BDC))
Perspective view of MIL-47 (VIV=O(BDC))