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2,6-Bis(1-alkyl-1H-1,2,3-triazol-4-yl)-pyridines: selective lipophilic chelating ligands for minor actinides


Starting from the promising minor actinides (MA) affinity showed by the water-soluble ligands (PyTri-polyols) with the 2,6-bis[1H-1,2,3-triazol-4-yl]-pyridine chelating unit, different attempts were made to functionalize the same N3-donor set with alkyl chains in the 1-position of triazole nuclei to obtain novel lipophilic extractants endowed with comparable MA selectivity. Solubility in organic diluents was found to be the main limitation to the development of efficient lipophilic ligands, thus resulting in less efficient extractants with respect to their hydrophilic analogues and sometimes impairing the selectivity evaluation. Interestingly, the ethyl hexyl derivative (PTEH) showed adequate extraction capability and a MA selectivity comparable to that of the hydrophilic PyTri family.

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  1. 1.

    IAEA (2010) Nuclear energy development in the 21st century: global scenarios and regional trends. IAEA Nuclear Energy Series, Vienna

    Google Scholar 

  2. 2.

    Poinssot Ch (2014) Assessment of the environmental footprint of nuclear energy systems. Comparison between closed and open fuel cycles. Energy 69:199–211

    Article  Google Scholar 

  3. 3.

    Leung DYC, Caramanna G, Maroto-Valer MM (2014) An overview of current status of carbon dioxide capture and storage technologies. Renew Sust Energ Rev 39:426–443

    CAS  Article  Google Scholar 

  4. 4.

    Silverio LB, Lamas WDQ (2011) An analysis of development and research on spent nuclear fuel reprocessing. Energy Policy 39:281–289

    CAS  Article  Google Scholar 

  5. 5.

    Gonzalez-Romero EM (2011) Impact of partitioning and transmutation on the high level waste management. Nucl Eng Des 241:3436–3444

    CAS  Article  Google Scholar 

  6. 6.

    Veliscek-Carolan J (2016) Separation of actinides from spent nuclear fuel: a review. J Hazard Mater 318:266–281

    CAS  Article  Google Scholar 

  7. 7.

    Bourg S, Hill C, Caravaca C, Rhodes C, Ekberg C, Taylor R, Geist A, Modolo G, Cassayre L, Malmbeck R, Harrison M, de Angelis G, Espartero A, Bouvet S, Ouvrier N (2011) ACSEPT—partitioning technologies and actinide science: towards pilot facilities in Europe. Nucl Eng Des 241:3427–3435

    CAS  Article  Google Scholar 

  8. 8.

    Modolo G, Wilden A, Geist A, Magnusson D, Malmbeck R (2012) A review of the demonstration of innovative solvent extraction processes for the recovery of trivalent minor actinides from PUREX raffinate. Radiochim Acta 100:715–725

    CAS  Article  Google Scholar 

  9. 9.

    Lewis FW (2015) Hydrophilic sulfonated bis-1,2,4-triazine ligands are highly effective reagents for separating actinides(III) from lanthanides(III) via selective formation of aqueous actinide complexes. Chem Sci 6:4812–4821

    CAS  Article  Google Scholar 

  10. 10.

    Edwards AC (2016) Exploring electronic effects on the partitioning of actinides(III) from lanthanides(III) using functionalised bis-triazinyl phenanthroline ligands. Dalton Trans 45:18102–18112

    CAS  Article  Google Scholar 

  11. 11.

    Hudson MJ (2013) Use of soft heterocyclic N-donor ligands to separate actinides and lanthanides. Inorg Chem 52:3414–3428

    CAS  Article  Google Scholar 

  12. 12.

    Leoncini A, Huskens J, Verboom W (2017) Ligands for f-element extraction used in the nuclear fuel cycle. Chem Soc Rev 46:7229–7273

    CAS  Article  Google Scholar 

  13. 13.

    Macerata E, Mossini E, Scaravaggi S, Mariani M, Mele A, Panzeri W, Boubals N, Berthon L, Charbonnel M-C, Sansone F, Arduini A, Casnati A (2016) Hydrophilic clicked 2,6-bis-triazolyl-pyridines endowed with high actinide selectivity and radiochemical stability: toward a closed nuclear fuel cycle. J Am Chem Soc 138:7232–7235

    CAS  Article  Google Scholar 

  14. 14.

    Wagner C, Mossini E, Macerata E, Mariani M, Arduini A, Casnati A, Geist A, Panak PJ (2017) Time-resolved laser fluorescence spectroscopy study of the coordination chemistry of a hydrophilic CHON [1,2,3-triazol-4-yl]pyridine ligand with Cm(III) and Eu(III). Inorg Chem 56:2135–2144

    CAS  Article  Google Scholar 

  15. 15.

    Mossini E, Macerata E, Wilden A, Kaufholz P, Modolo G, Iotti N, Casnati A, Geist A, Mariani M (2018) Optimization and single-stage centrifugal contactor experiments with the novel hydrophilic complexant PyTri-diol for the i-SANEX process. Solvent Extr Ion Exch 36:373–386.

    CAS  Article  Google Scholar 

  16. 16.

    Magnusson D, Christiansen B, Foreman MRS, Geist A, Glatz J-P, Malmbeck R, Modolo G, Serrano-Purroy D, Sorel C (2009) Demonstration of a SANEX process in centrifugal contactors using the CyMe4-BTBP molecule on a genuine fuel solution. Solvent Extr Ion Exch 27:97–106

    CAS  Article  Google Scholar 

  17. 17.

    Schmidt H, Wilden A, Modolo G, Švehla J, Grüner B, Ekberg C (2015) Gamma radiolytic stability of CyMe4BTBP and the effect of nitric acid. Nukleonica 60:879–884

    Article  Google Scholar 

  18. 18.

    Kiefer C, Wagner AT, Beele BB, Geist A, Panak PJ, Roesky PW (2015) A Complexation study of 2,6-bis(1-(p-tolyl)-1H-1,2,3-triazol-4-yl)pyridine using single-crystal X-ray diffraction and TRLFS. Inorg Chem 54:7301–7308

    CAS  Article  Google Scholar 

  19. 19.

    Mondal T, Basak D, Ouahabi AA, Schmutz M, Mésini P, Ghosh S (2015) Supporting information for Extended supramolecular organization of π-systems using yet unexplored simultaneous intra- and inter-molecular H-bonding motifs of 1,3-dihydroxy derivatives. Chem Commun 51:5040–5043

    CAS  Article  Google Scholar 

  20. 20.

    Orita A, Nakano T, An DL, Tanikawa K, Wakamatsu K, Otera J (2004) Metal-assisted assembly of pyridine-containing arylene ethynylene strands to enantiopure double helicates. J Am Chem Soc 126:10389–10396

    CAS  Article  Google Scholar 

  21. 21.

    Ostermeier M, Berlin MA, Meudtner RM, Demeshko S, Meyer F, Limberg C, Hecht S (2010) Complexes of click-derived bistriazolylpyridines: remarkable electronic influence of remote substituents on thermodynamic stability as well as electronic and magnetic properties. Chem Eur J 16:10202–10213

    CAS  Article  Google Scholar 

  22. 22.

    Ulrich S, Petitjean A, Lehn J-M (2010) Metallo-controlled dynamic molecular tweezers: design, synthesis, and self-assembly by metal-ion coordination. Eur J Inorg Chem 2010:1913–1928

    Article  Google Scholar 

  23. 23.

    Baek S-Y, Kim Y-W, Yoo S-H, Chung K, Kim N-K, Kim J-S (2012) Synthesis and rust preventing properties of dodecyl succinate derivatives containing triazole groups. Ind Eng Chem Res 51:9669–9678

    CAS  Article  Google Scholar 

  24. 24.

    Travelli C, Aprile S, Rahimian R, Grolla AA, Rogati F, Bertolotti M, Malagnino F, Di Paola R, Impellizzeri D, Fusco R, Mercalli V, Massarotti A, Stortini G, Terrazzino S, Del Grosso E, Fakhfouri G, Troiani MP, Alisi MA, Grosa G, Sorba G, Canonico PL, Orsomando G, Cuzzocrea S, Genazzani AA, Galli U, Tron GC (2017) Identification of novel triazole-based nicotinamide phosphoribosyltransferase (NAMPT) inhibitors endowed with antiproliferative and antiinflammatory activity. J Med Chem 60:1768–1792

    CAS  Article  Google Scholar 

  25. 25.

    Ishihara T, Ohwada K (1966) Chemical degradation of kerosene diluent with nitric acid. J Nucl Sci Technol 3:20–26

    CAS  Article  Google Scholar 

  26. 26.

    Nilsson M, Andersson S, Drouet F, Ekberg C, Foreman M, Hudson M, Liljenzin J-O, Magnusson D, Skarnemark G (2006) Extraction properties of 6,6′-bis-(5,6-dipentyl-[1, 2, 4]triazin-3-yl)-[2,2′]bipyridinyl (C5-BTBP). Solvent Extr Ion Exch 24:299–318

    CAS  Article  Google Scholar 

  27. 27.

    Retegan TV, Ekberg C, Fermvik A, Skarnemark G (2006) The effect of diluents on extraction of actinides and lanthanides. In: MRS proceedings 985, 0985-NN14-05.

  28. 28.

    Chapron S, Marie C, Arrachart G, Miguirditchian M, Pellet-Rostaing S (2015) New insight into the americium/curium separation by solvent extraction using diglycolamides. Solvent Extr Ion Exch 33:236–248

    CAS  Article  Google Scholar 

  29. 29.

    Modolo G, Kluxen P, Geist A (2010) Demonstration of the LUCA process for the separation of americium(III) from curium(III), californium(III), and lanthanides(III) in acidic solution using a synergistic mixture of bis(chlorophenyl)dithiophosphinic acid and tris(2-ethylhexyl)phosphate. Radiochim Acta 98:193–201

    CAS  Article  Google Scholar 

  30. 30.

    Vanel V, Marie C, Kaufholz P, Montuir M, Boubals N, Wilden A, Modolo G, Geist A, Sorel C (2016) Modeling and flowsheet design of an Am separation process using TODGA and H4TPAEN. Procedia Chem 21:223–230

    Article  Google Scholar 

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This work was supported by EU-FP7 ACSEPT (Grant No. 211267), SACSESS (Grant No. 323282), EU-H2020 GENIORS (Grant No. 755171) projects and by the Italian Ministry of Education, University and Research. Thanks are also due to Centro Interdipartimentale Misure “G. Casnati” of Parma University for NMR and mass measurements.

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Correspondence to Annalisa Ossola or Alessandro Casnati.

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The 1H and 13C NMR spectra of the synthetized ligands, as well as the extraction data, are reported in the Supplementary Information (DOC 538 kb)

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Ossola, A., Macerata, E., Mossini, E. et al. 2,6-Bis(1-alkyl-1H-1,2,3-triazol-4-yl)-pyridines: selective lipophilic chelating ligands for minor actinides. J Radioanal Nucl Chem 318, 2013–2022 (2018).

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  • Partitioning
  • Selective MA extraction
  • Nitrogen ligand
  • PyTri ligand
  • Click chemistry
  • Radioactive waste treatment