Separation of trivalent lanthanides （Ln（Ⅲ）） and actinides （An（Ⅲ）） is a key issue in the advanced spent nuclear fuel repro- cessing. In the well-known trivalent actinide lanthanide separation by phosphorus re...Separation of trivalent lanthanides （Ln（Ⅲ）） and actinides （An（Ⅲ）） is a key issue in the advanced spent nuclear fuel repro- cessing. In the well-known trivalent actinide lanthanide separation by phosphorus reagent extraction from aqueous komplexes （TALSPEAK） process, the organophosphorus ligand HDEHP （di-（2-ethylhexyl） phosphoric acid） has been used as an efficient reagent for the partitioning of Ln（Ⅲ） from An（Ⅲ） with the combination of a holdback reagent in aqueous lactate buffer solu- tion. In this work, the structural and electronic properties of Eu3＋ and Am3＋ complexes with HDEHP in nitric acid solution have been systematically explored by using scalar-relativistic density functional theory （DFT）. It was found that HDEHP can coordinate with M（Ⅲ） （M=Eu, Am） cations in the form of hydrogen-bonded dimers HL2 （L=DEHP）, and the metal ions pre- fer to coordinate with the phosphoryl oxygen atom of the ligand. For all the extraction complexes, the metal-ligand bonds are mainly ionic in nature. Although Eu（Ⅲ） complexes have higher interaction energies, the HL2- dimer shows comparable affini- ty for Eu（Ⅲ） and Am（Ⅲ） according to thermodynamic analysis, nonahydrate. It is expected that this work could provide insightful HDEHP at the molecular level. which may be attributed to the higher stabilities of Eu（Ⅲ） information on the complexation of An（Ⅲ） and Ln（Ⅲ） with展开更多
基金the National Natural Science Foundation of China (21201166, 11275090)the Major Research Plan of Natural Science Foundation of China (91426302, 91326202)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA030104)the Natural Science Foundation of Hunan Province (12JJ9006)the Scientific Research Fund of Hunan Provincial Education Department (12A116)
文摘Separation of trivalent lanthanides （Ln（Ⅲ）） and actinides （An（Ⅲ）） is a key issue in the advanced spent nuclear fuel repro- cessing. In the well-known trivalent actinide lanthanide separation by phosphorus reagent extraction from aqueous komplexes （TALSPEAK） process, the organophosphorus ligand HDEHP （di-（2-ethylhexyl） phosphoric acid） has been used as an efficient reagent for the partitioning of Ln（Ⅲ） from An（Ⅲ） with the combination of a holdback reagent in aqueous lactate buffer solu- tion. In this work, the structural and electronic properties of Eu3＋ and Am3＋ complexes with HDEHP in nitric acid solution have been systematically explored by using scalar-relativistic density functional theory （DFT）. It was found that HDEHP can coordinate with M（Ⅲ） （M=Eu, Am） cations in the form of hydrogen-bonded dimers HL2 （L=DEHP）, and the metal ions pre- fer to coordinate with the phosphoryl oxygen atom of the ligand. For all the extraction complexes, the metal-ligand bonds are mainly ionic in nature. Although Eu（Ⅲ） complexes have higher interaction energies, the HL2- dimer shows comparable affini- ty for Eu（Ⅲ） and Am（Ⅲ） according to thermodynamic analysis, nonahydrate. It is expected that this work could provide insightful HDEHP at the molecular level. which may be attributed to the higher stabilities of Eu（Ⅲ） information on the complexation of An（Ⅲ） and Ln（Ⅲ） with
