Multivariate Metal–Organic Framework-5 with 36 Different Linkers

We synthesized a series of multivariate metal-organic frameworks (MTV-MOFs) containing 36 different organic linkers with 27 unique functionalities. The functionalities present on the linkers include amine, nitro, halide, naphthalene, alkyne, alkene, alkane, ether, phenyl, pyridine, thiophene, and amide groups. These MTV-MOFs were characterized by powder X-ray diffraction to ensure the MOF-5 connectivity forms, solution-state nuclear magnetic resonance to calculate the final linker incorporations, thermogravimetric analysis to confirm the organic component of the framework, and nitrogen sorption isotherms to measure the porosity and calculate the BET surface areas of each MTV-MOF. Each linker was found to make up between 0.07 and 6.64% of the linkers in the structure, with the total framework mass consisting of 74.8-75.1% linker molecules, compared to 63.9% for the linkers in MOF-5. BET surface areas up to 1,755 m²/g were observed with 36 linkers present compared to 3,380 m²/g in MOF-5. Thirty-four of the 36 linkers had linear correlations between the starting ratio and final incorporation, indicating interactions between linkers do not heavily influence the incorporation of other linkers into the final structure.