Design criteria for tetradentate phenanthroline-derived heterocyclic ligands to separate Am(Ⅲ) from Eu(Ⅲ)  

作　　者：XIAO ChengLiang WU QunYan WANG CongZhi ZHAO YuLiang CHAI ZhiFang SHI WeiQun 

机构地区：[1]Key Laboratory of Nuclear Radiation and Nuclear Energy Technology [2]Key Laboratory For Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences [3]School of Radiological and Interdisciplinary Sciences, Soochow University

出　　处：《Science China Chemistry》2014年第11期1439-1448,共10页中国科学（化学英文版）

基　　金：supported by the Major Research Plan"Breeding and Transmutation of Nuclear Fuel in Advanced Nuclear Fission Energy System"of the National Natural Science Foundation of China(91326202,91126006);the National Natural Science Foundation of China(21201166,11275219,11105162,21261140335);the"Strategic Priority Research Program"of the Chinese Academy of Sciences(XDA030104);the China Postdoctoral Science Foundation(2013M530734)

摘　　要：To design novel phenanthroline-derived soft ligands for selectively separating minor actinides from lanthanides, four tetradentate phenanthroline-derived heterocyclic ligands(BTPhen, BPyPhen, BPzPhen, and BBizPhen) were constructed and their complexation behaviors with Am(ⅡI) and Eu(ⅡI) were systematically investigated by density functional theory(DFT) coupled with relativistic small-core pseudopotential. In all the 1:1-type species, the metal ion is in the center of the cavity and coordinates with two nitrogen atoms(N1 and N1′) of the phenanthroline skeleton and the other two nitrogen atoms(N2 and N2′) of the auxiliary groups. The bond lengths of Am–N are comparable to or even shorter than those of Eu–N bonds because the ionic radii of Am(ⅡI) are larger than those of Eu(ⅡI). Additionally, the negative ΔΔGAm/Eu value for the reaction of [M(H2O)4-(NO3)3] + L → ML(NO3)3 + 4H2 O indicates that the complexation reaction of Am(ⅡI) is more energetically favorable than that of Eu(ⅡI); this can be considered as an important design criterion to screen phenanthroline-derived ligands for MA(ⅡI) extraction. According to this criterion, the selectivity of tetradentate phenanthroline-derived ligands for separating Am(ⅡI) over Eu(ⅡI) follows the order of BTPhen > BBizPhen > BPyPhen > BPzPhen.To design novel phenanthroline-derived soft ligands for selectively separating minor actinides from lanthanides, four tetradentate phenanthroline-derived heterocyclic ligands（BTPhen, BPyPhen, BPzPhen, and BBizPhen） were constructed and their complexation behaviors with Am（ⅡI） and Eu（ⅡI） were systematically investigated by density functional theory（DFT） coupled with relativistic small-core pseudopotential. In all the 1：1-type species, the metal ion is in the center of the cavity and coordinates with two nitrogen atoms（N1 and N1′） of the phenanthroline skeleton and the other two nitrogen atoms（N2 and N2′） of the auxiliary groups. The bond lengths of Am–N are comparable to or even shorter than those of Eu–N bonds because the ionic radii of Am（ⅡI） are larger than those of Eu（ⅡI）. Additionally, the negative ΔΔGAm/Eu value for the reaction of [M（H2O）4-（NO3）3] ＋ L → ML（NO3）3 ＋ 4H2 O indicates that the complexation reaction of Am（ⅡI） is more energetically favorable than that of Eu（ⅡI）; this can be considered as an important design criterion to screen phenanthroline-derived ligands for MA（ⅡI） extraction. According to this criterion, the selectivity of tetradentate phenanthroline-derived ligands for separating Am（ⅡI） over Eu（ⅡI） follows the order of BTPhen 〉 BBizPhen 〉 BPyPhen 〉 BPzPhen.

关 键 词：minor actinide LANTHANIDE PHENANTHROLINE separation DFT 

分 类 号：O641.4[理学—物理化学]