Bhattacharyya Arunasis, Egberink Richard J M, Mohapatra Prasanta K, Verma Parveen K, Yadav Ashok K, Jha Sambhunath, Bhattacharyya Dibyendu, Huskens Jurriaan, Verboom Willem
Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai - 400 085, India.
Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Dalton Trans. 2017 Dec 21;46(47):16631-16639. doi: 10.1039/c7dt03329j. Epub 2017 Nov 23.
This paper reports the solvent extraction of Am and Eu using N,N,N',N',N'',N''-hexa-n-octylnitrilotriacetamide (HONTA) as the extractant in n-dodecane. The results are in variance with those reported previously with respect to the nature of the extracted species. The solvent extraction data were entirely different from those reported previously as the extracted species conformed to 1 : 2 (M : L) species for both Am and Eu ions. The structure of the extracted complex was determined by EXAFS demonstrating the three amidic 'O' atoms of the HONTA complex with the Eu ion. In the case of the Am ion, the pivotal 'N' atom is suggested to bond to the metal ion, which may explain the significantly more favourable extraction of Amvis-à-vis Eu. The absence of HO molecules in the inner coordination sphere of the Eu-HONTA extract was confirmed by luminescence spectroscopic measurements. Complexation studies in MeOH and EtOH indicated the formation of both 1 : 1 and 1 : 2 complexes with Nd ions. The results are explained on the basis of DFT calculations using HMNTA, the corresponding hexamethyl analogue of HONTA.
本文报道了以N,N,N',N',N'',N''-六正辛基次氮基三乙酰胺（HONTA）为萃取剂，在正十二烷中对镅和铕进行溶剂萃取的研究。就萃合物的性质而言，结果与先前报道的不同。由于对于镅和铕离子，萃合物符合1 : 2（M : L）型物种，所以溶剂萃取数据与先前报道的完全不同。通过扩展X射线吸收精细结构（EXAFS）确定了萃合物的结构，证明了HONTA与铕离子络合时的三个酰胺基“O”原子。对于镅离子，推测关键的“N”原子与金属离子键合，这可能解释了相对于铕，镅的萃取明显更有利。通过发光光谱测量证实了铕 - HONTA萃合物的内配位球中不存在水分子。在甲醇和乙醇中的络合研究表明与钕离子形成了1 : 1和1 : 2两种络合物。使用HMNTA（HONTA的相应六甲基类似物）通过密度泛函理论（DFT）计算对结果进行了解释。
