Fabrication of MOF Particle Assemblies for Structural Transformation Engineering

The structural flexibility of metal-organic frameworks (MOFs), which undergo structural changes upon gas adsorption, has been reported to depend on factors such as crystal structure, defects, and crystal size. On the other hand, MOFs are used as assemblies of crystals, such as pellets or membranes, but few studies have reported the effect on the flexibility in the assembly structure. In this study, we prepared assemblies of [Cu(NMe₂-ipa)] (NMe₂-KGM, NMe₂-ipa = 5-dimethylamino isophthalate). NMe₂-KGM with different packing densities and arrangements was used to compare the magnitude of structural changes during gas adsorption. It was found that structural changes of the MOFs in the regular assembly are suppressed compared to random assembly. The results of this study are expected to lead to new strategies for controlling flexibility through the design of crystal array structures.