Ansari Seraj A, Bhattacharyya Arunasis, Mohapatra Prasanta K, Egberink Richard J M, Huskens Jurriaan, Verboom Willem
Radiochemistry Division, Bhabha Atomic Research Centre Mumbai-400085 India
Laboratory of Molecular Nanofabrication, MESA+ Institute for Nanotechnology, University of Twente P. O. Box 217 7500 AE Enschede The Netherlands
RSC Adv. 2019 Oct 8;9(55):31928-31935. doi: 10.1039/c9ra05977f. eCollection 2019 Oct 7.
Two multiple diglycolamide (DGA)-containing extractants where the DGA arms are tethered to the nitrogen atoms of two aza-crown ether scaffolds, a 9-membered aza-crown ether containing three 'N' atoms (L) and a 12-membered aza-crown ether containing four 'N' atoms (L), were evaluated for the extraction of the tetravalent actinide ions Np and Pu. The tripodal ligand with three DGA arms (L) was relatively inferior in its metal ion extraction properties as compared to the tetrapodal ligand with four DGA arms (L) and Pu ion was better extracted than Np ion with both the ligands. A solvation extraction mechanism, where species of the type ML(NO) are extracted, was found to be operative for both the ligands involving both the tetravalent actinide ions. While the extraction of the metal ions increased with the feed nitric acid concentration up to 4 M, a sharp decline in the extraction was seen after that. Quantitative extraction (>99%) of the actinide ions was observed with L from 4 M HNO, suggesting the possible application of the ligands for actinide partitioning of high-level waste. The structure and the composition of the complexes were optimized by DFT computations.
研究了两种含多个二甘醇酰胺（DGA）的萃取剂，其中DGA臂连接到两个氮杂冠醚支架的氮原子上，一种是含有三个“N”原子的九元氮杂冠醚（L），另一种是含有四个“N”原子的十二元氮杂冠醚（L），用于萃取四价锕系离子Np和Pu。与具有四个DGA臂的四足配体（L）相比，具有三个DGA臂的三脚架配体（L）的金属离子萃取性能相对较差，并且两种配体对Pu离子的萃取都优于Np离子。发现一种溶剂化萃取机制，即ML(NO)类型的物种被萃取，对涉及两种四价锕系离子的两种配体都有效。虽然金属离子的萃取率随着进料硝酸浓度增加到4 M而增加，但在那之后萃取率急剧下降。用L从4 M HNO₃中观察到锕系离子的定量萃取（＞99%），表明这些配体在高放废物的锕系元素分离中可能有应用。通过密度泛函理论计算优化了配合物的结构和组成。
