2,6-Bis(5,6-diisopropyl-1,2,4-triazin-3-yl)pyridine

• Verfasst von: Beele, Björn B. [VerfasserIn]
• Verfasst von: Skerencak-Frech, Andrej [VerfasserIn]
• Verfasst von: Stein, Arnulf [VerfasserIn]
• Verfasst von: Trumm, Michael [VerfasserIn]
• Verfasst von: Wilden, Andreas [VerfasserIn]
• Verfasst von: Lange, Steve [VerfasserIn]
• Verfasst von: Modolo, Giuseppe [VerfasserIn]
• Verfasst von: Müllich, Udo [VerfasserIn]
• Verfasst von: Schimmelpfennig, Bernd [VerfasserIn]
• Verfasst von: Geist, Andreas [VerfasserIn]
• Verfasst von: Panak, Petra [VerfasserIn]
• Titel: 2,6-Bis(5,6-diisopropyl-1,2,4-triazin-3-yl)pyridine
• Titelzusatz: a highly selective N-donor ligand studied by TRLFS, liquid-liquid extraction and molecular dynamics
• Verf.angabe: Björn B. Beele, Andrej Skerencak-Frech, Arnulf Stein, Michael Trumm, Andreas Wilden, Steve Lange, Giuseppe Modolo, Udo Müllich, Bernd Schimmelpfennig, Andreas Geist and Petra J. Panak
• E-Jahr: 2016
• Jahr: 14th November 2016
• Umfang: 9 S.
• Fussnoten: Gesehen am 05.05.2020
• Titel Quelle: Enthalten in: New journal of chemistry
• Ort Quelle: London : RSC, 1987
• Jahr Quelle: 2016
• Band/Heft Quelle: 40(2016), 12, Seite 10389-10397
• ISSN Quelle: 1369-9261
• DOI: doi:10.1039/C6NJ02657E
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1697188494

Abstract

The complexation of Cm(III) and Eu(III) with 2,6-bis(5,6-di-i-propyl-1,2,4-triazin-3-yl)-pyridine (iPr-BTP) is studied in methanol : water (1 : 1, vol) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). With increasing ligand concentration [Cm(iPr-BTP)3]3+ and [Eu(iPr-BTP)3]3+ are formed, respectively. Stability constants of log β3′([Cm(iPr-BTP)3]3+) = 16.3 ± 0.3 and log β3′([Eu(iPr-BTP)3]3+) = 14.9 ± 0.3 are determined. Thermodynamic data of the complexation reactions is obtained in a temperature range of 20-60 °C. The complexation of iPr-BTP with both metal ions is exothermic (Cm(III): ΔrH3′ = −(64.1 ± 3.0) kJ mol−1; Eu(III): ΔrH3′ = −(42.6 ± 2.0) kJ mol−1). The reaction entropy for the formation of [Eu(iPr-BTP)3]3+ is higher compared to the Cm(III) complex (Cm(III): ΔrS3′ = (96.5 ± 6.5) J mol−1 K−1; Eu(III): ΔrS3′ = (136.0 ± 15.2) J mol−1 K−1). Different complexation entropies for the formation of [Cm(iPr-BTP)3] and [Cm(nPr-BTP)3] are explained by molecular dynamics simulations. Results from liquid-liquid extraction tests confirm the ligand's peculiar extraction kinetics observed in previous studies and link them to the thermodynamic data.