Isoreticular Contraction of Cage-like Metal-Organic Frameworks with Optimized Pore Space for Enhanced CH/CO and CH/CH Separations.

The CH separation from CO and CH is of great importance yet highly challenging in the petrochemical industry, owing to their similar physical and chemical properties. Herein, the pore nanospace engineering of cage-like mixed-ligand MFOF-1 has been accomplished via contracting the size of the pyridine- and carboxylic acid-functionalized linkers and introducing a fluoride- and sulfate-bridging cobalt cluster, based on a reticular chemistry strategy. Compared with the prototypical MFOF-1, the constructed FJUT-1 with the same topology presents significantly improved CH adsorption capacity, and selective CH separation performance due to the reduced cage cavity size, functionalized pore surface, and appropriate pore volume.

Optimized Pore Nanospace through the Construction of a Cagelike Metal-Organic Framework for CO/N Separation.

The development of metal-organic framework (MOF) adsorbents with a potential molecule sieving effect for CO capture and separation from flue gas is of critical importance for reducing the CO emissions to the atmosphere yet challenging. Herein, a cagelike MOF with a suitable cage window size falling between CO and N and the cavity has been constructed to evaluate its CO/N separation performance. It is noteworthy that the introduction of coordinated dimethylamine (DMA) and ,'-dimethylformamide (DMF) molecules not only significantly reduces the cage window size but also enhances the framework-CO interaction via C-H···O hydrogen bonds, as proven by molecular modeling, thus leading to an improved CO separation performance.