Xinrui Zhang currently works at the Institute of High Energy Physics, Chinese Academy of Sciences as a Ph.D. student. Major in novel ligands developing for lanthanides and actinides separation.
Research Items (5)
- Apr 2019
The group actinide extraction ligand, N,N′-diethyl-N,N′-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen)has been successfully developed in our laboratory recently. In this work, the extraction behaviors of the tetradentate Et-Tol-DAPhen toward Am(III)and Pu(IV)by using 1-(trifluoromethyl)-3-nitrobenzene as the diluent were systematically explored. The effects of HNO 3 and ligand concentration as well as temperature were studied in detail. In addition, the selectivity of this ligand towards actinides and the stripping performance of the extraction system were also investigated to assess its potential application for group actinide separation over trivalent lanthanides (Ln(III)). According to our results, Et-Tol-DAPhen exhibits large distribution ratios for both Am(III)and Pu(IV)with high separation factors over Pm(III)in a wide range of acidity. Moreover, Am(III)and Pu(IV)can be efficiently stripped into the aqueous phase via three stages of batch back extraction. In addition, density functional theory (DFT)calculations suggest that the ligand selectivity towards actinides over Ln(III)probably results from the higher covalency of An-N bonds. The consistency between calculated thermodynamic parameters and experimental observations demonstrates the reasonability of the proposed extraction mechanism. Our findings afford insightful extraction parameters of Et-Tol-DAPhen towards actinides with different oxidation states and justify its versatile coordination abilities with respect to group actinide separation over lanthanides.
- Apr 2018
2,9-Diamide-1,10-phenanthroline (DAPhen) ligands represent a new family of tetradentate extractants given their strong affinity to actinides and the CHON principle. Among this family, N,N′-diethyl-N,N′-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen), initially reported by us, exhibits excellent selectivity towards actinides (U, Th, Am, Pu) over lanthanides and thus can be potentially applied in the group actinide extraction (GANEX) process for the group separation of actinides. In this article, by tailoring the lengths of alkyl chains, we synthesized other four DAPhen ligands with different substitute groups in the diamide moieties, and characterized the relationship between properties and substitute groups of DAPhen ligand. The extraction results show that three of the ligands exhibit high performance in UO2²⁺ extraction from an acidic solution and the extracted UO2²⁺ can be easily stripped by only using ultrapure water. Spectrophotometry titration confirms that UO2²⁺ combined with all the four ligands in 1:1 mode. The extended X-ray absorption finestructure (EXAFS) study shows that six donor atoms comprise the first equatorial shell of the UO2²⁺ ions bonded by the DAPhen ligands, among which two nitrogen and two oxygen atoms are from the DAPhen ligand, while other two oxygen atoms are from one nitrate ions. This article promises to provide basic data for assessing the feasibility of this kind of DAPhen ligands applied in actinides separation from nuclear wastes.
- May 2016
A novel tetradentate ligand combining hard O-donor and soft N-donors in the same molecule, N,N’-diethyl-N,N’-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen), was developed in our laboratory aiming at the group separation of actinides from lanthanides. Herein, the solvent extraction of UO22+ by Et-Tol-DAPhen in 1-(trifluoromethyl)-3-nitrobenzene diluent was investigated in detail. The effects of contact time, Et-Tol-DAPhen concentration, acidity, and competing ions on the extraction were discussed, the extracted UO22+ speciation was analyzed, and the stripping of UO22+ from organic phase was performed. The results clearly show that Et-Tol-DAPhen/1-(trifluoromethyl)-3-nitrobenzene provides a highly efficient extraction of UO22+ from HNO3 media with a fast extraction kinetics of less than 5 min and a large distribution ratio of more than 300. Moreover, the system shows excellent selectivity toward UO22+ over Ln3+ in a wide acidity range. Stripping experiments indicate that almost a complete back extraction of UO22+ could be achieved via only one stage operation using 5% Na2CO3 solution. Findings of the present work provide new data for assessing the feasibility of Et-Tol-DAPhen, as well as other new ligand with hard−soft donors combined in the same molecule, applied in the group separation of actinides over lanthanides.
Question - Is there some book or public material about solvent extraction of inorganic species?
Separation and Purification Technology
Separation Science and Technology
The two journals also include some papers about solvent extraction.
The tetradentate N,N’-diethyl-N,N’-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen) ligand with hard-soft donor atoms has been demonstrated to be promising for the group separation of actinides from highly acidic nuclear wastes. To identify its formed complexes with actinides and lanthanides, electrospray ionization mass spectrometry (ESI-MS) combined with density functional theoretical (DFT) calculations was used to probe the possible complexation process. The 1:2 Eu-L species ([EuL2(NO3)]2+) can be observed in ESI-MS at low metal-to-ligand ([M]/[L]) ratios whereas 1:1 Eu-L species ([EuL(NO3)2]+) can be observed when the [M]/[L] ratio is higher than 1.0. However, ([UO2L(NO3)]+) is the only detected species for uranyl complexes. The [ThL2(NO3)2]2+ species can be observed at low [M]/[L] ratio; the 1:2 species ([ThL2(NO3)]3+) and a new 1:1 species ([ThL(NO3)3]+) can be detected at high [M]/[L] ratios. Collision-induced dissociation (CID) results showed that Et-Tol-DAPhen ligands can coordinate strongly with metal ions and the coordination moieties remain intact under CID conditions. Natural bond orbital (NBO), molecular electrostatic potential (MEP), electron localization function (ELF), atoms in molecules (AIM) and molecular orbital (MO) analyses indicated that the metal-ligand bonds of actinide complexes exhibited more covalent characters than lanthanide complexes. Additionally, according to thermodynamic analysis, the stable cationic M-L complexes in acetonitrile are found to be in good agreement with the ESI-MS results.