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Fargher HA, Delmau LH, Bryantsev VS, Haley MM, Johnson DW, Moyer BA. Disrupting the Hofmeister bias in salt liquid-liquid extraction with an arylethynyl bisurea anion receptor. Chem Sci 2024; 15:5311-5318. [PMID: 38577371 PMCID: PMC10988605 DOI: 10.1039/d3sc05922g] [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: 11/06/2023] [Accepted: 03/04/2024] [Indexed: 04/06/2024] Open
Abstract
Host-mediated liquid-liquid extraction is a convenient method for the separation of inorganic salts. However, selective extraction of an anion, regardless of its hydrophilicity or lipophilicity as qualitatively described by its place in the Hofmeister series, remains challenging. Herein we report the complete disruption of the Hofmeister-based ordering of anions in host-mediated extraction by a rigidified tweezer-type receptor possessing remarkably strong anion-binding affinity under the conditions examined. Experiments introduce a convenient new method for determination of anion binding using phosphorus inductively coupled plasma mass spectrometry (ICP-MS) to measure extraction of tetra-n-butylphosphonium (TBP+) salts from water into nitrobenzene, specifically examining the disrupting effect of the added arylethynyl bisurea anion receptor. In the absence of the receptor, the salt partitioning follows the expected Hofmeister-type ordering favoring the larger, less hydrated anions; the analysis yields the value -24 kJ mol-1 for the standard Gibbs energy of partitioning of TBP+ cation from water into nitrobenzene at 25 °C. Selectivity is markedly changed by the addition of receptor to the nitrobenzene and is concentration dependent, giving rise to three selectivity regimes. We then used SXLSQI liquid-liquid equilibrium analysis software developed at Oak Ridge National Laboratory to fit host-mediated extraction equilibria for TBP+ salts of Cl-, Br-, I-, and NO3- to the distribution data. While the reverse-Hofmeister 1 : 1 binding of the anions by the receptor effectively cancels the Hofmeister selectivity of the TBPX partitioning into nitrobenzene, formation of unexpected 2 : 1 receptor : anion complexes favoring Cl- and Br- dominates the selectivity at elevated receptor concentrations, producing the unusual order Br- > Cl- > NO3- > I- in anion distribution wherein a middle member of the series is selected and the most lipophilic anion is disfavored. Density functional theory calculations confirmed the likelihood of forming 2 : 1 complexes, where Cl- and Br- are encapsulated by two receptors adopting energetically competitive single or double helix structures. The calculations explain the rare non-Hofmeister preference for Br-. This example shows that anion receptors can be used to control the selectivity and efficiency of salt extraction regardless of the position of the anion in the Hofmeister series.
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Affiliation(s)
- Hazel A Fargher
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon Eugene OR 97403-1253 USA
| | - Lætitia H Delmau
- Radioisotope Science and Technology Division, Oak Ridge National Laboratory Oak Ridge TN 37831-6384 USA
| | | | - Michael M Haley
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon Eugene OR 97403-1253 USA
| | - Darren W Johnson
- Department of Chemistry and Biochemistry, Materials Science Institute, University of Oregon Eugene OR 97403-1253 USA
| | - Bruce A Moyer
- Chemical Sciences Division, Oak Ridge National Laboratory Oak Ridge TN 37831-6119 USA
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Kuzmin VI, Gudkova NV, Kuzmin DV, Kondrasenko AV, Leskiv MN. Effect of solvation-dehydration of quaternary ammonium base salts in the organic phase on the selectivity of anion-exchange extraction. SEP SCI TECHNOL 2023. [DOI: 10.1080/01496395.2023.2189053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Affiliation(s)
- Vladimir I. Kuzmin
- Institute of Chemistry and Chemical Technology SB RAS Federal Research Center, ”Krasnoyarsk Science Center SB RAS”, Krasnoyarsk, Russia
| | - Natalia V. Gudkova
- Institute of Chemistry and Chemical Technology SB RAS Federal Research Center, ”Krasnoyarsk Science Center SB RAS”, Krasnoyarsk, Russia
| | - Dmitriy V. Kuzmin
- Institute of Chemistry and Chemical Technology SB RAS Federal Research Center, ”Krasnoyarsk Science Center SB RAS”, Krasnoyarsk, Russia
| | - Alexander V. Kondrasenko
- Institute of Chemistry and Chemical Technology SB RAS Federal Research Center, ”Krasnoyarsk Science Center SB RAS”, Krasnoyarsk, Russia
| | - Marina N. Leskiv
- Institute of Chemistry and Chemical Technology SB RAS Federal Research Center, ”Krasnoyarsk Science Center SB RAS”, Krasnoyarsk, Russia
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Seipp CA, Williams NJ, Bryantsev VS, Moyer BA. Simple guanidinium motif for the selective binding and extraction of sulfate. SEP SCI TECHNOL 2017. [DOI: 10.1080/01496395.2017.1318922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Charles A. Seipp
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Neil J. Williams
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee, USA
| | | | - Bruce A. Moyer
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Williams NJ, Bryanstev VS, Custelcean R, Seipp CA, Moyer BA. α,α′,α″,α′″-meso-tetrahexyltetramethyl-calix[4]pyrrole: an easy-to-prepare, isomerically pure anion extractant with enhanced solubility in organic solvents. Supramol Chem 2016. [DOI: 10.1080/10610278.2015.1120873] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Neil J. Williams
- Oak Ridge National Laboratory, Chemical Science Division, Oak Ridge, TN, USA
- Department of Chemistry, The University of Tennessee, Knoxville, TN, USA
| | | | - Radu Custelcean
- Oak Ridge National Laboratory, Chemical Science Division, Oak Ridge, TN, USA
| | - Charles A. Seipp
- Oak Ridge National Laboratory, Chemical Science Division, Oak Ridge, TN, USA
- Department of Chemistry, The University of Texas at Austin, Austin, TX, USA
| | - Bruce A. Moyer
- Oak Ridge National Laboratory, Chemical Science Division, Oak Ridge, TN, USA
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Busschaert N, Caltagirone C, Van Rossom W, Gale PA. Applications of Supramolecular Anion Recognition. Chem Rev 2015; 115:8038-155. [PMID: 25996028 DOI: 10.1021/acs.chemrev.5b00099] [Citation(s) in RCA: 852] [Impact Index Per Article: 94.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | - Claudia Caltagirone
- ‡Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, S.S. 554 Bivio per Sestu, 09042 Monserrato, Cagliari, Italy
| | - Wim Van Rossom
- †Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Philip A Gale
- †Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Kim SK, Lee J, Williams NJ, Lynch VM, Hay BP, Moyer BA, Sessler JL. Bipyrrole-strapped calix[4]pyrroles: strong anion receptors that extract the sulfate anion. J Am Chem Soc 2014; 136:15079-85. [PMID: 25254498 DOI: 10.1021/ja5086996] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cage-type calix[4]pyrroles 2 and 3 bearing two additional pyrrole groups on the strap have been synthesized. Compared with the parent calix[4]pyrrole (1), they were found to exhibit remarkably enhanced affinities for anions, including the sulfate anion (TBA(+) salts), in organic media (CD2Cl2). This increase is ascribed to participation of the bipyrrole units in anion binding. Receptors 2 and 3 extract the hydrophilic sulfate anion (as the methyltrialkyl(C(8-10))ammonium (A336(+)) salt) from aqueous media into a chloroform phase with significantly improved efficiency (>10-fold relative to calix[4]pyrrole 1). These two receptors also solubilize into chloroform the otherwise insoluble sulfate salt, (TMA)2SO4 (tetramethylammonium sulfate).
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Affiliation(s)
- Sung Kuk Kim
- Department of Chemistry, The University of Texas at Austin , 105 E. 24th Street, Stop A5300, Austin, Texas 78712-1224, United States
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Moyer BA, Custelcean R, Hay BP, Sessler JL, Bowman-James K, Day VW, Kang SO. A case for molecular recognition in nuclear separations: sulfate separation from nuclear wastes. Inorg Chem 2012; 52:3473-90. [PMID: 23134587 DOI: 10.1021/ic3016832] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this paper, we present the case for molecular-recognition approaches for sulfate removal from radioactive wastes via the use of anion-sequestering systems selective for sulfate, using either liquid-liquid extraction or crystallization. Potential benefits of removing sulfate from the waste include improved vitrification of the waste, reduced waste-form volume, and higher waste-form performance, all of which lead to potential cleanup schedule acceleration and cost savings. The need for sulfate removal from radioactive waste, especially legacy tank wastes stored at the Hanford site, is reviewed in detail and primarily relates to the low solubility of sulfate in borosilicate glass. Traditional methods applicable to the separation of sulfate from radioactive wastes are also reviewed, with the finding that currently no technology has been identified and successfully demonstrated to meet this need. Fundamental research in the authors' laboratories targeting sulfate as an important representative of the class of oxoanions is based on the hypothesis that designed receptors may provide the needed ability to recognize sulfate under highly competitive conditions, in particular where the nitrate anion concentration is high. Receptors that have been shown to have promising affinity for sulfate, either in extraction or in crystallization experiments, include hexaurea tripods, tetraamide macrocycles, cyclo[8]pyrroles, calixpyrroles, and self-assembled urea-lined cages. Good sulfate selectivity observed in the laboratory provides experimental support for the proposed molecular-recognition approach.
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Affiliation(s)
- Bruce A Moyer
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6119, USA.
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