Metal-organic frameworks (MOFs) have drawn tremendous amount of attention due to their fascinating structural topologies and potential applications in a wide range of areas, including strategic storage and separation of gases, catalysis ,chemical sensing, and drug delivery.
Depending on the specific needs of an application, the overall structure of a MOF,
e.g. porosity and surface functions, could be designed and finetuned through the judicious choices of metal/metal-containing building nodes and organic bridging ligands.
As for an example, the well-known paddle-wheel-like Cu2(COO)4 motif, in which the axial positions could be occupied by either solvent molecules or N-donor ligands, has resulted in the formation of a large number of highly porous MOFs.
Thus, ligands at different axial positions affect the properties of these porous materials.