Structural clues to UO22+/VO2+ competition in seawater extraction using amidoxime-based extractantsElectronic supplementary information (ESI) available: Experimental details, additional characterization, crystal structure refinement details, and in-depth structure analyses. CCDC 1018650-1018652. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4cc06370h

Here we present the first structural comparison of amidoxime complexes of UO 2 2+ and VO 2 + (the main competitor in the extraction of uranium from seawater using amidoxime-based sorbents) using a 4,5-di(amidoxime)-functionalized imidazole ligand. The amidoxime groups resist tautomerization in both cases and quite different coordination modes (chelating vs. bridging) are observed. The first direct structural comparison of UO 2 2+ and VO 2 + amidoxime complexes are reported using a 4,5-di(amidoxime)-functionalized imidazole ligand.