2,6-Bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine as a ligand for efficient actinide(III)/lanthanide(III) separation

Antje Bremer; Christian M Ruff; Denise Girnt; Udo Müllich; Jörg Rothe; Peter W Roesky; Petra J Panak; Alexei Karpov; Thomas J J Müller; Melissa A Denecke; Andreas Geist

doi:10.1021/ic3000526

2,6-Bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine as a ligand for efficient actinide(III)/lanthanide(III) separation

Inorg Chem. 2012 May 7;51(9):5199-207. doi: 10.1021/ic3000526. Epub 2012 Apr 19.

Authors

Antje Bremer¹, Christian M Ruff, Denise Girnt, Udo Müllich, Jörg Rothe, Peter W Roesky, Petra J Panak, Alexei Karpov, Thomas J J Müller, Melissa A Denecke, Andreas Geist

Affiliation

¹ Institut für Nukleare Entsorgung, Karlsruher Institut für Technologie, P.O. Box 3640, 76021 Karlsruhe, Germany.

PMID: 22515352
DOI: 10.1021/ic3000526

Abstract

The N-donor complexing ligand 2,6-bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine (C5-BPP) was synthesized and screened as an extracting agent selective for trivalent actinide cations over lanthanides. C5-BPP extracts Am(III) from up to 1 mol/L HNO(3) with a separation factor over Eu(III) of approximately 100. Due to its good performance as an extracting agent, the complexation of trivalent actinides and lanthanides with C5-BPP was studied. The solid-state compounds [Ln(C5-BPP)(NO(3))(3)(DMF)] (Ln = Sm(III), Eu(III)) were synthesized, fully characterized, and compared to the solution structure of the Am(III) 1:1 complex [Am(C5-BPP)(NO(3))(3)]. The high stability constant of log β(3) = 14.8 ± 0.4 determined for the Cm(III) 1:3 complex is in line with C5-BPP's high distribution ratios for Am(III) observed in extraction experiments.