Mitchell Lauren A, Holliday Bradley J
Department of Chemistry, The University of Texas at Austin, 105 E. 24th Street, Stop A5300, Austin, Texas 78712-0165, United States.
ACS Macro Lett. 2016 Oct 18;5(10):1100-1103. doi: 10.1021/acsmacrolett.6b00596. Epub 2016 Sep 15.
The ability of carbamoylmethylphosphine oxide (CMPO) ligands to selectively chelate actinides has been shown to be enhanced by preorganizing the ligands on molecular scaffolds. To increase the preorganization, a new polymeric material with a polyoxanorbornene backbone and CMPO ligand pendant groups has been synthesized, and the ability of the material to selectively extract actinides utilizing a biphasic extraction strategy has been tested. In liquid-liquid extractions of -block metals from acidic aqueous media into an organic solution containing chelating materials, the polymeric material exhibited a significantly higher ability to extract Th ions than the monomer, with an order of magnitude greater affinity for the polymeric material in most cases. Due to the unique properties of polymeric materials versus small molecules, additional questions arose as to the effect of molecular weight on extraction efficiency. Extraction and separation efficiencies varied for materials of differing molecular weights, with the largest molecular weight polymer extracting near quantitative amounts of thorium ions, and the smaller molecular weight polymers showing separation factors for Th ions over Ce, La, and Eu ions ranging from 124 to 328.
通过在分子支架上预组织氨基甲酰甲基氧化膦（CMPO）配体，已证明其选择性螯合锕系元素的能力得到增强。为了增强预组织效果，合成了一种具有聚氧杂降冰片烯主链和CMPO配体侧基的新型聚合材料，并测试了该材料利用双相萃取策略选择性萃取锕系元素的能力。在从酸性水介质到含有螯合材料的有机溶液的液-液萃取中，该聚合材料对钍离子的萃取能力明显高于单体，在大多数情况下，对聚合材料的亲和力高一个数量级。由于聚合材料与小分子相比具有独特的性质，因此出现了关于分子量对萃取效率影响的其他问题。不同分子量的材料萃取和分离效率各不相同，分子量最大的聚合物能萃取接近定量的钍离子，分子量较小的聚合物对钍离子相对于铈、镧和铕离子的分离因子在124至328之间。
