Ligand functionalization of defect-engineered Ni-MOF-74

Incorporating functionality into the framework of metal-organic frameworks (MOFs) has attracted substantial interest because the physical and chemical properties of MOFs can be tuned by functionalizing pores. The ligand functionalization of MOF-74 is challenging because of its pristine organic ligand and framework structure. Herein, we report a series of ligand-functionalized Ni-MOF-74 derivatives synthesized by defect engineering using a mixed-ligand approach. Defect generation and ligand functionalization of Ni-MOF-74 were simultaneously achieved by incorporation of fragmented organic ligands such as 5-formylsalicylic acid, 3-hydroxysalicylic acid, 2-hydroxynicotinic acid and 5-hydroxy-1H-benzimidazole-4-carboxylic acid. The resulting defect-engineered Ni-MOF-74 derivatives maintained relatively good crystallinity up to fragment incorporation levels of similar to 20% and exhibited modified permanent porosity and CO2 adsorption properties depending on the functional groups and defect concentrations in the framework.

Automated summary

Incorporating functionality into MOFs has attracted interest due to the tunability of their properties. Ligand functionalization of MOF-74 is challenging, but this study successfully achieved defect generation and ligand functionalization using fragmented organic ligands. The resulting defect-engineered Ni-MOF-74 derivatives maintained good crystallinity and exhibited modified porosity and CO2 adsorption properties.