Liu Mengjia, He Ying, Wojtas Lukasz, Shi Xiaodong
Department of Chemistry, University of South Florida, Tampa, FL 33620 (USA).
Green Chem. 2023 Nov 7;25(21):8494-8499. doi: 10.1039/d3gc02932h. Epub 2023 Oct 4.
The isoguanosine self-assembled pentamer (isoG-star) has exhibited remarkable selectivity for Cs binding over competing alkali and alkali earth metal cation, rendering it a promising extractor for radioactive waste Cs separation. However, to make isoG-star a pracrtical material for Cs isolation, the development of recyclable isoG-star material is required. In this study, a systematic screening of functional isoG derivatives was performed. By employing well-defined complex formation and post-assembly modification, a covalently tethered isoG-star was prepared through olefin metathesis, utilizing a designed isoG monomer. The application of this newly developed covalently linked isoG-star enabled selective Cs extraction, followed by controled solvent-induced H-bond dessociation. This resulted in the creation of a recyclable Cs extractor, demonstrating excellent cation selectivity and good reusability (over seven cycles) the first time. Consequently, this new supramolecular macrocycle offers a practical new platform for the treatment of radiocesium (Cs and Cs) in an environmentally friendly and highly effective manner.
异鸟苷自组装五聚体（isoG-star）对铯的结合表现出对竞争性碱金属和碱土金属阳离子的显著选择性，使其成为放射性废物铯分离的有前途的萃取剂。然而，要使isoG-star成为用于铯分离的实用材料，需要开发可回收的isoG-star材料。在本研究中，对功能性异鸟苷衍生物进行了系统筛选。通过采用明确的络合形成和组装后修饰，利用设计的异鸟苷单体，通过烯烃复分解制备了共价连接的isoG-star。这种新开发的共价连接的isoG-star的应用实现了选择性铯萃取，随后通过可控的溶剂诱导氢键解离。这导致创建了一种可回收的铯萃取剂，首次展示了优异的阳离子选择性和良好的可重复使用性（超过七个循环）。因此，这种新的超分子大环为以环境友好和高效的方式处理放射性铯（铯-137和铯-134）提供了一个实用的新平台。
