Metallazyklen der Selten-Erd-Elemente mit verbrückten Bisamidinatliganden für die Katalyse und Liganden für die Actinoiden/Lanthanoiden Trennung (English shop)

Preview

Table of Contents, Datei (70 KB)
Extract, Datei (320 KB)

Denise Girnt’s dissertation investigates the synthesis and characterization of novel rare-earth metal complexes containing bridged bisamidinate ligands and the development of selective ligands for actinide/lanthanide separation. The first part focuses on synthesizing bisamidines with rigid aromatic bridging groups, particularly dibenzofuran and 9,9-dimethylxanthene, and using them to prepare multinuclear lanthanide complexes. These reactions produce novel dinuclear and tetranuclear metallacycles, whose molecular structures are investigated through spectroscopic methods and single-crystal X-ray diffraction. The potential of these ligand systems for catalytic applications is also considered. The second part examines pyridine-based nitrogen-donor ligands for selectively separating trivalent actinides from chemically similar lanthanides. Complexes containing samarium, europium, americium, and curium are synthesized or investigated. Their coordination properties are characterized using EXAFS and time-resolved laser fluorescence spectroscopy. Extraction experiments demonstrate particularly high separation selectivity for a symmetrical bispyrazolylpyridine ligand. The findings contribute to understanding f-block coordination chemistry and developing selective extraction ligands for nuclear waste treatment.