Researchers from KAUST have developed a metal organic framework (MOF) mimicking a class of inorganic porous materials called zeolites. Their zeolite-inspired MOF can be modified to change pore structure simply by swapping out different metals and organic linkers. Their findings are published in the Journal of the American Chemical Society.
MOFs are crystalline materials composed of metal ions connected by organic linkers. You can think of the frameworks as building blocks that repeat the same structures over and over to produce larger complex structures. MOFs are of interest to the scientific community because they can store molecules and be used for gas sensing or molecular separations. Watch the video below to learn more about MOFs.
The MOF that the KAUST researchers have designed is more porous than other materials. Lead researcher Norah Alsadun explains, "Our group introduced the use of single-metal-based tetrahedral building units for zeolite-like MOF (ZMOF) construction. The basis of the tetrahedron-based ZMOF structure is a pair of triangular pyramids, attached tip-to-tip via a single bond.”
These structures interact to form networks of angles that block the pores in the framework. "So, we developed a new concept for ZMOF assembly using polynuclear clusters as rigid, directional, and locked-in building units," adds Mohamed Eddaoudi, whose lab led the study. The bonds between the tetrahedrons lock the structure into a particular orientation and result in pores with diameters up to 43 angstroms. As such, they are the largest pores to date observed for a ZMOF.
The team is hopeful for the implications that their design holds. "Our work proves that these challenging structures can be accessed through our novel design," Eddaoudi says. "Applying this strategy to construct other ZMOFs is now in progress."