129Xe NMR study of xenon in iso-reticular metal–organic frameworks

Hyperpolarized 129Xe NMR spectroscopy is used to investigate the interaction of xenon with four different zinc metal–organic frameworks, IRMOF-1, -7, -8, and -10. Each of the frameworks has a cubic cage of varying size, depending on the organic linker molecule. The 129Xe NMR chemical shifts are influenced by both the cage dimensions and the distribution of xenon within the framework. NMR spectra acquired at low temperature suggest that high xenon loadings can be achieved using the continuous-flow hyperpolarized 129Xe NMR experiment. Information about the adsorption energy is inferred from the behaviour of the xenon chemical shifts as a function of temperature and analyzed for IRMOF-10. The rate at which xenon diffuses through the IRMOF is probed using a signal recovery NMR experiment.