Complete multinuclear solid-state NMR of metal-organic frameworks: The case of α-Mg-formate

Abstract

Metal-organic frameworks (MOFs) are exciting porous materials with a growing number of applications ranging from catalysis to gas storage. Establishing logical connections between the local MOF structure and its properties is not often straightforward, however, solid-state NMR is a sensitive probe of local structure and can be used to shed light on processes such as guest adsorption and gas motion within MOFs. As illustrated using our recent works on the microporous α-Mg-formate (Mg3(HCOO)6) MOF, complete multinuclear solid-state NMR characterization of MOFs is now possible, and can provide unique insight that is not readily available through other methods. A wide variety of solid-state NMR techniques have been employed, including direct-excitation, cross-polarization, fast magic-angle spinning, and two-dimensional experiments. New variable-temperature 2H solid-state NMR data of deuterated hydrogen gas within α-Mg-formate and the resulting detailed dynamic information is also presented, analyzed, and discussed.