Influence of the solvent on the complexation of Cm(III) and Eu(III) with nPr-BTP studied by time-resolved laser fluorescence spectroscopy
The complexation of Cm(III) and Eu(III) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (nPr-BTP) in methanol-water mixtures with varying water content is investigated by TRLFS. For both metal ions, the exclusive formation of the 1 : 3 complex is observed in each solvent mixture. Stability con...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
2015
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| In: |
New journal of chemistry
Year: 2014, Volume: 39, Issue: 2, Pages: 1330-1338 |
| ISSN: | 1369-9261 |
| DOI: | 10.1039/C4NJ01900H |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1039/C4NJ01900H Verlag, lizenzpflichtig, Volltext: https://pubs.rsc.org/en/content/articlelanding/2015/nj/c4nj01900h 
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| Author Notes: | Antje Bremer, Udo Müllich, Andreas Geist and Petra J. Panak |
| Summary: | The complexation of Cm(III) and Eu(III) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (nPr-BTP) in methanol-water mixtures with varying water content is investigated by TRLFS. For both metal ions, the exclusive formation of the 1 : 3 complex is observed in each solvent mixture. Stability constants are determined by analysis of the fluorescence spectra. As a result, an immense influence of the water content is found. The stability constant of the [Cm(nPr-BTP)3]3+ complex increases by three orders of magnitude when the water content in methanol-water mixtures is reduced (log β3 = 14.3 ± 0.1 at 50 vol% water content; log β3 = 17.4 ± 0.4 at 5 vol% water content). Due to the preferential solvation of Cm(III) by water in methanol-water mixtures, the increase is moderate at water contents between 50 vol% and 20 vol% and becomes steeper at lower water contents. For the [Eu(nPr-BTP)3]3+ complex, an analogous evolution of the stability constant is observed (log β3 = 12.0 ± 0.1 at 50 vol% water content; log β3 = 14.7 ± 0.4 at 5 vol% water content). Therefore, the difference between the stability constants of the Cm(III) and Eu(III) 1 : 3 complexes is constant at all solvent mixtures investigated (Δlog β3 = 2.3 ± 0.3) which means that the selectivity of the N-donor ligand is not influenced by the solvent. |
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| Item Description: | First published 11 December 2014 Gesehen am 28.05.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1369-9261 |
| DOI: | 10.1039/C4NJ01900H |