Mechanosynthesis of new azine-functionalized Zn(ii) metal–organic frameworks for improved catalytic performance†
Three 3D, porous Zn(II)-based metal–organic frameworks, TMU-4, TMU-5 and TMU-6, containing azine-functionalized pores, were readily and quickly prepared via mechanosynthesis. Catalytic performance of these MOFs and the effect of N-donor ligands with diverse basicity in the Knoevenagel condensation reaction are investigated. Increasing the basicity of N-donor ligands leads to improvement in catalytic activity. Results show that among the three compounds, TMU-5 has the highest catalytic activity upon increasing its basicity of azine function in the N-donor ligand. These catalysts maintain their crystalline framework after the reaction and are easily recycled.