Tuning water adsorption, stability, and phase in Fe-MIL-101 and Fe-MIL-88 analogs with amide functionalization

Abstract

Metal–organic frameworks (MOFs) of the MIL series of materials have been widely studied as a result of their high tunability and the diversity of structure types that exist for these typically M³⁺ containing frameworks. We explored the use of amide-functionalized ligands in the synthesis of Fe-MIL-101 as a means to tune the water stability and water vapor adsorption in this important class of frameworks. We further show that slow leaching of Fe from NdFeB magnets can afford MIL-101 or MIL-88 under various conditions where the phase of the framework is controlled by length of the carbon chains on amide substituents. NdFeB can also be used to prepare these materials at room temperature in the absence of additional metal salts.