Research paper of the month
February 2015 -Stronger metal-organic frameworks
The ability to retain structural integrity under processing conditions which involve mechanical stress is essential if metal–organic frameworks (MOFs) are to fulfil their potential as serious candidates for use in gas sorption, separation, catalysis and energy conversion applications. Here we provide the first steps towards strengthening the physical properties of a selection of MOFs through replacement of cluster bridging ligands with electron withdrawing groups.
Figure: The increase in resistance to framework collapse upon ball-milling of a selection of Zr-containing MOFs. Whilst resistance increases with decreasing porosity, highly porous frameworks such as UiO-66, Zr6O4(OH)4[O2C–C6H4–CO2]6, can be stabilized by replacing a benzene dicarboxylate ligand with trifluroacetate (TFA). Green polyhedra – ZrO clusters, Pink – TFA molecules.
B. Van de Voorde, I. Stassen, B. Bueken, F. Vermoortele, D. De Vos, R. Ameloot, J.-C, Tan and T. D. Bennett, “Improving the mechanical stability of zirconium-based metal–organic frameworks by incorporation of acidic modulators” J. Mater. Chem. A, 3 (2015) 1737-1742