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Pu N, Archer E, He X, Chen J, Rao L, Shafer JC, Yang P, Xu C. Tuning Selectivity to f-Elements through Bonding and Solvation Effects of a Sulfur Donor Ligand. Inorg Chem 2024; 63:6845-6853. [PMID: 38568878 DOI: 10.1021/acs.inorgchem.4c00297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Bis(2,4,4-trimethylpentyl)dithiophosphinic acid, commonly referred to as HBTMPDTP or Cyanex301, is a sulfur-donating ligand that shows considerable promise in the challenging task of separating trivalent actinides (An3+) from lanthanides (Ln3+). Although its effectiveness has been established, the specific molecular details about the preference of HBTMPDTP for americium over europium have remained a mystery, puzzling researchers for over two decades. This study presents a comprehensive, dual-driven separation mechanism for this complex system combining experimental and theoretical approaches. A critical finding is the increased covalency in An-S bonds compared to Ln-S bonds, which plays a significant role in HBTMPDTP's intrinsic selectivity for An3+ over Ln3+. This leads to the formation of distinct An3+ and Ln3+ species, enhancing the ligand's actinide selectivity. Additionally, it provides crucial insights into the coordination chemistry of f-elements with sulfur-donating ligands, thereby deepening our understanding of this intricate field.
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Affiliation(s)
- Ning Pu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Emma Archer
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Xihong He
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Jing Chen
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Linfeng Rao
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jenifer C Shafer
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Ping Yang
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Chao Xu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
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2
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Pu N, Xu C, Chen J. Probing Substituent Effect on Nickel-Sulfur Bond Covalency in Ni(II)-Dithiophosphinate Complexes by Sulfur K-Edge XAS and DFT Calculations. Inorg Chem 2023; 62:15565-15574. [PMID: 37700628 DOI: 10.1021/acs.inorgchem.3c02062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Complexes of Ni(II) with a series of aryl or alkyl substituent dithiophosphinic acids were characterized by crystallographic structure, sulfur K-edge X-ray absorption spectroscopy (XAS), and density functional theory (DFT). In these complexes, Ni(II) coordinates with four sulfur atoms from two dithiophosphinate anions form a well-defined square-planar structure. Despite the minor differences in the geometry parameters among the complexes, the electronic structure is affected significantly by the substituent group attached to dithiophosphinic acid. In particular, the addition of ortho-CF3 group to the aryl ring constrains the orientation of the aryl ring and enhances the conjugation between the aryl ring and the coordinating core. Sulfur K-edge XAS spectra help further reveal the electronic structure of the complexes. Both the pre-edge feature and rising-edge feature provide abundant information on the molecular orbitals and show a distinctive effect of the substituent groups on the electronic structure of the complexes, which is supposedly relevant to the ligand's performance in Ln(III)/An(III) separation.
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Affiliation(s)
- Ning Pu
- Sinopec Research Institute of Petroleum Processing Co. Ltd., Beijing 100083, China
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Chao Xu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Jing Chen
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
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Xu C, Zhu L, Liu Q, Yang S, Xue Y, Tian G. A study on the extraction of actinides with a novel carboxylic acid extractant. J Radioanal Nucl Chem 2023. [DOI: 10.1007/s10967-022-08706-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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4
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Zhang Y, Duan W, Wang Q, Zheng L, Wang J, Chen J, Sun T. Covalency between the uranyl ion and dithiophosphinate by sulfur K-edge X-ray absorption spectroscopy and density functional theory. JOURNAL OF SYNCHROTRON RADIATION 2022; 29:11-20. [PMID: 34985418 PMCID: PMC8733989 DOI: 10.1107/s160057752101198x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
The dithiophosphinic acids (HS2PR2) have been used for the selective separation of trivalent actinides (AnIII) from lanthanides (LnIII) over the past decades. The substituents on the dithiophosphinic acids dramatically impact the separation performance, but the mechanism is still open for debate. In this work, two dithiophosphinic acids with significantly different AnIII/LnIII separation performance, i.e. diphenyl dithiophosphinic acid (HS2PPh2) and bis(ortho-trifluoromethylphenyl) dithiophosphinic acid [HS2P(o-CF3C6H4)2], are employed to understand the substituent effect on the bonding covalency between the S2PR2- anions (R = Ph and o-CF3C6H4) and the uranyl ion by sulfur K-edge X-ray absorption spectroscopy (XAS) in combination with density functional theory calculations. The two UO2(S2PR2)(EtOH) complexes display similar XAS spectra, in which the first pre-edge feature with an intensity of 0.16 is entirely attributed to the transitions from S 1s orbitals to the unoccupied molecular orbitals due to the mixing between U 5f and S 3p orbitals. The Mulliken population analysis indicates that the amount of \% S 3p character in these orbitals is essentially identical for the UO2(S2PPh2)2(EtOH) and UO2[S2P(o-CF3C6H4)2]2(EtOH) complexes, which is lower than that in the U 6d-based orbitals. The essentially identical covalency in U-S bonds for the two UO2(S2PR2)2(EtOH) complexes are contradictory to the significantly different AnIII/LnIII separation performance of the two dithiophosphinic acids, thus the covalency seems to be unable to account for substituent effects in the AnIII/LnIII separation by the dithiophosphinic acids. The results in this work provide valuable insight into the understanding of the mechanism in the AnIII/LnIII separation by the dithiophosphinic acids.
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Affiliation(s)
- Yusheng Zhang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Wuhua Duan
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Qiang Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Lei Zheng
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jianchen Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jing Chen
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, People's Republic of China
| | - Taoxiang Sun
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, People's Republic of China
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Yang X, Wang S, Xu L, Yan Q, Xu C, Matveev P, Lei L, Xiao C. New tetradentate N, O-hybrid phenanthroline-derived organophosphorus extractants for the separation and complexation of trivalent actinides and lanthanides. Inorg Chem Front 2022. [DOI: 10.1039/d2qi01153k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Comparison of the extraction and separation properties between two novel phenanthroline-derived organophosphorus ligands, Et-Ph-BPPhen and Et-Ph-PIPhen.
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Affiliation(s)
- Xiao Yang
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Shihui Wang
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Lei Xu
- Institute of Nuclear-Agricultural Science, Zhejiang University, Hangzhou 310058, China
| | - Qiang Yan
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Chao Xu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Petr Matveev
- Radiochemistry Division, Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russian Federation
| | - Lecheng Lei
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Chengliang Xiao
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
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Chapleski RC, Ivanov AS, Peterson KA, Bryantsev VS. Improving the theoretical description of Ln(III)/An(III) separation with phosphinic acid ligands: a benchmarking study of structure and selectivity. Phys Chem Chem Phys 2021; 23:19558-19570. [PMID: 34524309 DOI: 10.1039/d1cp02466c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The efficient separation of trivalent lanthanides from minor actinides with soft-donor ligands, while showing experimental promise, has theorists continuing to search for suitable approaches for describing and interpreting selectivity. To remedy this, we employ several computational methods in describing the structure of model M(H2PX2)3 complexes, with M = Eu and Am, and X = O, S, Se, and Te, and predicting the selectivity of model phosphinic acid ligands in Eu(III)/Am(III) separation. After first establishing a set of MP2 and CCSD(T)-DKH3 results as benchmarks, we evaluate several density functionals and descriptions of valence shells for their accuracy with respect to metal-ligand bonding and selectivity. We find that commonly employed functionals with a 0-27% range of exact exchange used with small-core effective core potentials or with an explicit treatment of the relativistic effects (DKH2) incorrectly predict a decrease in the metal-ligand bond distance in going from Eu(III) to Am(III) and completely fail to track a selectivity trend, even giving a wrong sign for some or all ligands. Surprisingly, when these functionals are used in conjunction with an f-in-core description of metal ions, the correct trend in selectivity is recovered, though Am-X distances are overestimated in relation to Eu-X. Functionals with high components of exact exchange (50%) and double-hybrid functionals are reasonably aligned with benchmark results, pointing to the problems of DFT with small exact exchange fractions to handle f-electrons. Natural bond orbital analyses reveal that these poorly performing functionals disproportionately overpopulate outer f orbitals in the model complexes. We anticipate that recommendations resulting from this work will lead to more accurate theoretical descriptions of lanthanide/actinide selectivity with soft-donor chalcogen-based ligands in the future.
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Affiliation(s)
- Robert C Chapleski
- Chemical Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 27831, USA.
| | - Alexander S Ivanov
- Chemical Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 27831, USA.
| | - Kirk A Peterson
- Department of Chemistry, Washington State University, Pullman, WA 99164, USA.
| | - Vyacheslav S Bryantsev
- Chemical Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 27831, USA.
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Lipin R, Ebenezer C, Solomon RV. Theoretical evaluation of mixed N-, O- donor based TMPhenDA ligand in selective complexation with actinide (III) ions over lanthanide (III) ions. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115819] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Bessen N, Bertelsen ER, Shafer JC. Permanganometric Titration for the Quantification of Purified Bis(2,4,4-trimethylpentyl)dithiophosphinic Acid in n-Dodecane. ACS OMEGA 2021; 6:8463-8468. [PMID: 33817507 PMCID: PMC8015081 DOI: 10.1021/acsomega.1c00254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
The organic soluble extractant bis(2,4,4-trimethylpentyl)dithiophosphinic acid, often called Cyanex 301 (HC301), has shown selectivity for preferentially extracting trivalent actinides over the lanthanides in the treatment of used nuclear fuel. To maintain control and efficiency of a separation process using this extractant, it is necessary to accurately know specific parameters of the system, including the concentration of HC301 in the organic phase, at any given time. Here, the ability to quickly determine the concentration of HC301 in n-dodecane was tested by a one-step permanganometric titration in an organic solution using a double-beam UV-vis spectrophotometer. The addition of HC301 in n-dodecane to solutions of KMnO4 was found to decolorize the KMnO4 solutions, but the HC301 was best quantified in terms of decolorization in acetone. This decolorization allowed for the creation of a linear analytical curve relating the amount of KMnO4 consumed to the amount of HC301 added. Cross-validation of this analytical curve reproduced the known amount of HC301 with an average difference of 1.73% and a maximum of 4.03%.
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Affiliation(s)
- Nathan
P. Bessen
- Colorado
School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United
States
| | - Erin R. Bertelsen
- University
of Massachusetts Lowell, 220 Pawtucket Street, Lowell, Massachusetts 01854, United States
| | - Jenifer C. Shafer
- Colorado
School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United
States
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Yang X, Xu L, Hao Y, Meng R, Zhang X, Lei L, Xiao C. Effect of Counteranions on the Extraction and Complexation of Trivalent Lanthanides with Tetradentate Phenanthroline-Derived Phosphonate Ligands. Inorg Chem 2020; 59:17453-17463. [DOI: 10.1021/acs.inorgchem.0c02728] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xiao Yang
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Lei Xu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yuxun Hao
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Ruixue Meng
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Xingwang Zhang
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Lecheng Lei
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Chengliang Xiao
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
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11
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Pu N, Su J, Xu L, Sun T, Batista ER, Chen J, Yang P, Shafer JC, Xu C. “Sweeping” Ortho Substituents Drive Desolvation and Overwhelm Electronic Effects in Nd3+ Chelation: A Case of Three Aryldithiophosphinates. Inorg Chem 2019; 59:161-171. [DOI: 10.1021/acs.inorgchem.9b01931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ning Pu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Jing Su
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Lei Xu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Taoxiang Sun
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Enrique R. Batista
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jing Chen
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Ping Yang
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Jenifer C. Shafer
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Chao Xu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
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