A TRLFS study on the complexation of novel BTP type ligands with Cm(III)
Two BTP-type N-donor ligands with different numbers of aromatic nitrogen atoms (2,6-bis(4-ethyl-pyridazin-1-yl)pyridine, Et-BDP and 2,6-bis(4-npropyl-2,3,5,6-tetrazine-1-yl)pyridine, nPr-Tetrazine) have been synthesized and characterized by NMR and MS techniques. The complexation with Cm(III) in 2-p...
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| Main Authors: | , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
25 Mar 2013
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| In: |
Dalton transactions
Year: 2013, Volume: 42, Issue: 34, Pages: 12139-12147 |
| ISSN: | 1477-9234 |
| DOI: | 10.1039/C3DT50536G |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1039/C3DT50536G Verlag, lizenzpflichtig, Volltext: https://pubs.rsc.org/en/content/articlelanding/2013/dt/c3dt50536g 
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| Author Notes: | Björn B. Beele, Elias Rüdiger, Felicitas Schwörer, Udo Müllich, Andreas Geist and Petra J. Panak |
| Summary: | Two BTP-type N-donor ligands with different numbers of aromatic nitrogen atoms (2,6-bis(4-ethyl-pyridazin-1-yl)pyridine, Et-BDP and 2,6-bis(4-npropyl-2,3,5,6-tetrazine-1-yl)pyridine, nPr-Tetrazine) have been synthesized and characterized by NMR and MS techniques. The complexation with Cm(III) in 2-propanol-water (1 : 1, vol.) is studied for both ligands using time resolved laser-induced fluorescence spectroscopy (TRLFS) and the complexation properties are compared to nPr-BTP. With increasing the ligand concentration three different species, the 1 : 1-, 1 : 2- and 1 : 3-complex, were found. Log β3 values of 7.6 for the formation of Cm(Et-BDP)3 and 9.2 for the formation of Cm(nPr-Tetrazine)3 are determined. The complexation with nPr-Tetrazine shows slow kinetics. Thermodynamic data of the complexation reactions are determined in a temperature range of 25 °C-60 °C. The complexation with Et-BDP is exothermic (ΔH = −16.3 ± 1.2 kJ mol−1) and exergonic (ΔG = −43.8 ± 2.6 kJ mol−1) whereas the complexation with nPr-Tetrazine is endothermic (ΔH = 43.9 ± 3.1 kJ mol−1) and exergonic (ΔG = −51.7 ± 2.2 kJ mol−1). In the case of the latter the complexation is driven by a highly positive reaction entropy change (ΔS = 320.6 ± 15.4 J mol−1 K−1). In comparison to nPr-BTP, less negative ΔG values were found for the complexation of Cm(III) with both ligands. |
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| Item Description: | Gesehen am 30.11.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1477-9234 |
| DOI: | 10.1039/C3DT50536G |