Actinide Center for Excellence

Farha has previously demonstrated that at sufficiently acidic pHs, the MOF NU-1000 is neutral (Klet, R. C. et al. J. Mater. Chem. A, 2016, 4, 1479-1485) allowing anionic polyoxometalates (POMs) to replace hydroxide/aqua ligands on the node and impregnate the pores of the MOF (Buru, C. T. et al. Submitted). Advantageously, powder X-ray diffraction (PXRD) patterns of the resultant material matched that of a simulated pattern of the structure in which the POM sits in the interstitial spaces between adjacent nodes. Deleterious leaching of the POM was minimized due to the fortuitous matching of the POM size with the cavity in the MOF. Strikingly, the installed POMs were retained within the framework even at a pH below 2 with concomitant competitive exposure to chloride ions. Farha and Burns propose an analogous installation of a pre-synthesized Pu(VI) clusters—in a MOF. In order to better accommodate larger clusters, the window size of the MOF can be modified ranging from 10 to 19 Å via modification of the organic linkers, while retaining consistent topology