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Weberg AB, Dembowski M, Blad QK, Goff GS, Hanson SK, May I. Scaling high-speed counter-current chromatography for preparative neodymium purification: Insights and challenges. J Chromatogr A 2024; 1729:465033. [PMID: 38852269 DOI: 10.1016/j.chroma.2024.465033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/14/2024] [Accepted: 05/25/2024] [Indexed: 06/11/2024]
Abstract
Efficient rare earth element (REE) separations are becoming increasingly important to technologies ranging from renewable energy and high-performance magnets to applied radioisotope separations. These separations are made challenging by the extremely similar chemical and physical characteristics of the individual elements, which almost always occupy the 3+ oxidation state under ambient conditions. Herein, we discuss the development of a novel REE separation aimed at obtaining purified samples of neodymium (Nd) on a multi-milligram scale using high-speed counter-current chromatography (HSCCC). The method takes advantage of the subtle differences in ionic radii between neighboring REEs to tune elution rates in dilute acid through implementation of the di-(2-ethylhexyl)phosphoric acid (HDEHP)-infused stationary phase (SP) of the column. A La/Ce/Nd/Sm separation was demonstrated at a significantly higher metal loading than previously accomplished by HSCCC (15 mg, RNd/REE > 0.85), while the Pr/Nd separation was achieved at lower metal loadings (0.3 mg, RNd/Pr = 0.75 - 0.83). The challenges associated with scaling REE separations via HSCCC are presented and discussed within.
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Affiliation(s)
- Alexander B Weberg
- Chemistry - Nuclear and Radiochemistry (C-NR), Los Alamos National Laboratory, Mail Stop J-514, Los Alamos NM 87545, USA.
| | - Mateusz Dembowski
- Materials Synthesis and Integrated Devices (MPA-11), Los Alamos National Laboratory, Mail Stop J-514, Los Alamos NM 87545, USA
| | - Quintin K Blad
- Materials Synthesis and Integrated Devices (MPA-11), Los Alamos National Laboratory, Mail Stop J-514, Los Alamos NM 87545, USA
| | - George S Goff
- Materials Synthesis and Integrated Devices (MPA-11), Los Alamos National Laboratory, Mail Stop J-514, Los Alamos NM 87545, USA
| | - Susan K Hanson
- Chemistry - Nuclear and Radiochemistry (C-NR), Los Alamos National Laboratory, Mail Stop J-514, Los Alamos NM 87545, USA
| | - Iain May
- Chemistry - Nuclear and Radiochemistry (C-NR), Los Alamos National Laboratory, Mail Stop J-514, Los Alamos NM 87545, USA
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Kofod N, Henrichsen MJ, Sørensen TJ. Mapping the distribution of electronic states within the 5D 4 and 7F 6 levels of Tb 3+ complexes with optical spectroscopy. Dalton Trans 2024; 53:4461-4470. [PMID: 38372338 DOI: 10.1039/d3dt03657j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
The Tb(III) ion has the most intense luminescence of the trivalent lanthanide(III) ions. In contrast to Eu(III), where the two levels only include a single state, the high number of electronic states in the ground (7F6) and emitting (5D4) levels makes detailed interpretations of the electronic structure-the crystal field-difficult. Here, luminescence emission and excitation spectra of Tb(III) complexes with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA, [Tb(DOTA)(H2O)]-), ethylenediaminetetraacetic acid (EDTA, [Tb(EDTA)(H2O)3]-) and diethylenetriaminepentaacetic acid (DTPA, [Tb(DTPA)(H2O)]2-) as well as the Tb(III) aqua ion ([Tb(H2O)9]3+) were recorded at room temperature and in frozen solution. Using these data the electronic structure of the 5D4 multiplets of Tb(III) was mapped by considering the transitions to the singly degenerate 7F0 state. A detailed spectroscopic investigation was performed and it was found that the 5D4 multiplet could accurately be described as a single band for [Tb(H2O)9]3+, [Tb(DOTA)(H2O)]- and [Tb(EDTA)(H2O)3]-. In contrast, for [Tb(DTPA)(H2O)]2- two bands were needed. These results demonstrated the ability of describing the electronic structure of the emitting 5D4 multiplet using emission spectra. This offers an avenue for investigating the relationship between molecular structure and luminescent properties in detailed photophysical studies of Tb(III) ion complexes.
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Affiliation(s)
- Nicolaj Kofod
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Margrete Juel Henrichsen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Thomas Just Sørensen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
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Nielsen LG, Sørensen TJ. Effect of buffers and pH in antenna sensitized Eu(III) luminescence. Methods Appl Fluoresc 2023; 11. [PMID: 36696692 DOI: 10.1088/2050-6120/acb63a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/25/2023] [Indexed: 01/26/2023]
Abstract
The photophysics of a europium(III) complex of 1,4,7,10-tetraazacycododecane-1,4,7-triacetic acid-10-(2-methylene)-1-azathioxanthone was investigated in three buffer systems and at three pH values. The buffers-phosphate buffered saline (PBS), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), and universal buffer (UB)-had no effect on the europium luminescence, but a lower overall emission intensity was determined in HEPES. It was found that this was due to quenching of the 1-azathioxanthone first excited singlet state by HEPES. The effect of pH on the photophysics of the complex was found to be minimal, and protonation of the pyridine nitrogen was found to be irrelevant. Even so, pH was shown to change the intensity ratio between 1-azathioxanthone fluorescence and europium luminescence. It was concluded that the full photophysics of a potential molecular probe should be investigated to achieve the best possible results in any application.
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Affiliation(s)
- Lea Gundorff Nielsen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, København Ø, Denmark
| | - Thomas Just Sørensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, København Ø, Denmark
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Alexander C, Thom JA, Kenwright AM, Christensen KE, Sørensen TJ, Faulkner S. Chelating chloride using binuclear lanthanide complexes in water. Chem Sci 2023; 14:1194-1204. [PMID: 36756316 PMCID: PMC9891377 DOI: 10.1039/d2sc05417e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/27/2022] [Indexed: 12/28/2022] Open
Abstract
Halide recognition by supramolecular receptors and coordination complexes in water is a long-standing challenge. In this work, we report chloride binding in water and in competing media by pre-organised binuclear kinetically inert lanthanide complexes, bridged by flexible -(CH2)2- and -(CH2)3- spacers, forming [Ln2(DO3A)2C-2] and [Ln2(DO3A)2C-3], respectively. These hydrophilic, neutral lanthanide coordination complexes are shown to bind chloride with apparent association constants of up to 105 M-1 in water and in buffered systems. Hydroxide bridging was observed in these complexes at basic pH, which was proven to be overcome by chloride. Thus, these lanthanide complexes show promise towards chloride recognition in biology and beyond. The results described here have clearly identified a new area of anion coordination chemistry that is ripe for detailed exploration.
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Affiliation(s)
- Carlson Alexander
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
| | - James A Thom
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
| | - Alan M Kenwright
- Department of Chemistry, University of Durham South Road Durham DH1 3LE UK
| | - Kirsten E Christensen
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
| | - Thomas Just Sørensen
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
- Nano-Science Centre and Department of Chemistry, University of Copenhagen 2100 København Ø Denmark
| | - Stephen Faulkner
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
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Mortensen SS, Marciniak Nielsen MA, Nawrocki P, Sørensen TJ. Electronic Energy Levels and Optical Transitions in Samarium(III) Solvates. J Phys Chem A 2022; 126:8596-8605. [DOI: 10.1021/acs.jpca.2c04793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Sabina Svava Mortensen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Malthe Asmus Marciniak Nielsen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Patrick Nawrocki
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Thomas Just Sørensen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
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Thomsen MS, Nawrocki PR, Kofod N, Sørensen TJ. Seven Europium(III) Complexes in Solution – the Importance of Reporting Data When Investigating Luminescence Spectra and Electronic Structure. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Maria S. Thomsen
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Patrick R. Nawrocki
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Nicolaj Kofod
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
| | - Thomas J. Sørensen
- Department of Chemistry and Nano-Science Center University of Copenhagen Universitetsparken 5 2100 København Ø Denmark
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Storm Thomsen M, Sørensen TJ. Delicate, a study of the structural changes in ten-coordinated La( iii), Ce( iii), Pr( iii), Nd( iii), Sm( iii) and Eu( iii) sulfates. Dalton Trans 2022; 51:8964-8974. [DOI: 10.1039/d2dt00832g] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A study of doped ten-coordinated structures of the lanthanide(iii) crystals series, K6[Ln2(SO4)6] (Ln(iii) = La, Ce, Pr) and K5Na[Ln2(SO4)6] (Ln(iii) = Nd, Sm, Eu) to determine luminescence from Eu(iii) in distorted host lattices.
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Affiliation(s)
- Maria Storm Thomsen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Thomas Just Sørensen
- Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
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