Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Nat Commun. 2019 Feb 18;10(1):819. doi: 10.1038/s41467-019-08758-1.
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) recognition motifs possessing siderophore-like selectivity, however, presents a challenge. Herein we report a comprehensive theoretical, crystallographic and spectroscopic studies on the UO binding with a non-toxic siderophore-inspired chelator, 2,6-bis[hydroxy(methyl)amino]-4-morpholino-1,3,5-triazine (HBHT). The optimal pK values and structural preorganization endow HBHT 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 HBHT-functionalized polymeric adsorbent material that affords high uranium uptake capacity even in the presence of competing vanadium (V) ions in aqueous medium.
数千年来，大自然通过采用各种超分子螯合剂进化出了选择性识别和隔离特定金属离子的能力。铁特异性分子载体-铁载体-以其结构优雅而引人注目，同时对特定金属离子表现出最强和最选择性的结合。然而，开发具有铁载体样选择性的简单铀（UO）识别基序是一个挑战。本文报道了对 UO 与一种无毒的铁载体模拟螯合剂 2,6-双[羟甲基（甲）氨基]-4-吗啉-1,3,5-三嗪（HBHT）结合的全面理论、晶体学和光谱学研究。最佳 pK 值和结构预组织使 HBHT 成为分子螯合剂中铀结合亲和力和选择性最高的一种。小分子标准品的结果通过 HBHT 功能化聚合物吸附剂材料的原理验证得到证实，即使在水介质中存在竞争的钒（V）离子，该材料仍具有高的铀吸附容量。
