Ph.D. topics

Synthesis and characterization of heterobimetallic actinide-transition metal complexes and their conversion into organometallic frameworks

Dennis Grödler

Prof. Dr. Thorsten Stumpf, Dr. Robert Gericke (HZDR)

Chemie der f-Elemente

05/2023-04/2026

The presence of long-lived radionuclides, such as plutonium, in radioactive waste poses a particular challenge due to their high chemical and radiotoxicity. This requires concepts that guarantee safe disposal for at least one million years. It is therefore necessary to consolidate the knowledge gathered to date about these transuranic elements and pass it on to future generations. However, since the discovery of the transuranium elements neptunium and plutonium, which are particularly relevant here, was only 84 years ago, significantly fewer properties have been researched in comparison to uranium and thorium. The coordination of very soft donor atoms, especially late transition metals, to actinides has been studied little or not at all. Part of this work will therefore deal with the formation of actinide-metal bonds. Only 67 structures have been published in the CCDC that form a bond between an actinide (Th or U) and a transition metal. Actinides in particular are predicted to interact strongly with transition metals in the form of multiple bonds. These stable structures then represent basic motifs, which will be extended to metal-organic frameworks in a further part of the work. These so-called metal-organic frameworks (MOFs) will then be tested for their immobilization capabilities of mobile fission products such as ¹²⁹I and ⁹⁹TcO₄⁻. These An-TM-MOFs will be investigated as alternative waste matrices in comparison to concreting and vitrification to immobilize both actinides and anionic long-lived fission products.

This work is part of the “Am-BALL” project, which is funded by the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) under grant number 1501667.