Chapter 6 - Mechanochemical synthesis of metal–organic frameworks

Abstract

Metal–organic frameworks (MOFs) are porous crystalline materials made of coordination-bridged multi-dentate organic ligands and metal ions or clusters. Owing to their large specific surface area, high porosity, flexible size, facile structural modification, and diverse functionalities, they have prospective uses in gas adsorption, separation, and catalysis. Mechanochemical techniques, which refer to reactions carried out by solid-state grinding of reactants with no or very little solvent, have increasingly gained popularity as a clean, green, and effective synthesis technique among the several widely used methods for MOFs so far. Recent studies reveal that the mechanochemical approach is an environmentally friendly synthetic process that enables the synthesis of MOFs and their composites in large quantities at low cost. The most well-known MOFs, including MOF-5, MIL-101, ZIF-8, HKUST-1, and UiO-66, were created using the mechanochemical approach. MOFs prepared by this method possess higher specific surface areas, in comparison to the analogous MOFs obtained by traditional solvent-based techniques. The aim of this chapter is to offer an overview of current trends in the mechanochemical production of MOFs and their composites. In addition to covering the mechanochemical synthesis of MOFs, this chapter highlights several laboratory approaches for in situ and in real-time monitoring of the progress of mechanochemical conversions at the molecular level.