Siderophore-inspired chelator hijacks uranium from aqueous medium.

Ivanov, Alexander S; Parker, Bernard F; Zhang, Zhicheng; Aguila, Briana; Sun, Qi; Ma, Shengqian; Jansone-Popova, Santa; Arnold, John et al. · Nat Commun · 2019

basic_science · Level V

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Abstract

Over millennia, nature has evolved an ability to selectively recognize and sequester specific metal ions by employing a wide variety of supramolecular chelators. Iron-specific molecular carriers-siderophores-are noteworthy for their structural elegance, while exhibiting some of the strongest and most selective binding towards a specific metal ion. Development of simple uranyl (UO<sub>2</sub><sup>2+</sup>) recognition motifs possessing siderophore-like selectivity, however, presents a challenge. Herein we report a comprehensive theoretical, crystallographic and spectroscopic studies on the UO<sub>2</sub><sup>2+</sup> binding with a non-toxic siderophore-inspired chelator, 2,6-bis[hydroxy(methyl)amino]-4-morpholino-1,3,5-triazine (H<sub>2</sub>BHT). The optimal pK<sub>a</sub> values and structural preorganization endow H<sub>2</sub>BHT with one of the highest uranyl binding affinity and selectivity among molecular chelators. The results of small-molecule standards are validated by a proof-of-principle development of the H<sub>2</sub>BHT-functionalized polymeric adsorbent material that affords high uranium uptake capacity even in the presence of competing vanadium (V) ions in aqueous medium.