Actinide Bonding – Comparative Study of Isostructural An(IV) Imine Complexes


Actinide Bonding – Comparative Study of Isostructural An(IV) Imine Complexes

Radoske, T.; Kaden, P.; Schöne, S.; Ikeda-Ohno, A.; Stumpf, T.

Because of their unique electronic properties originating from 5f-orbitals, the coordination chemistry of actinides (An) is still an attractive research field in terms not only of nuclear engineering but also of basic chemistry. In particular, the early An show profound complex chemistry due to a wide variety of possible oxidation states ranging from +II to +VII, which is in contrast to the dominant trivalent state for their chemical analog of lanthanides. The aim of our research activities is to gain knowledge about the interaction of An with a variety of hard- and soft-donor ligands, eventually providing a comprehensive understanding of the electronic nature of actinide compounds. The ligands used in this study possess both O- (i.e. hard) and N-donor (soft) containing functionalities (Fig.1) and could also be considered as a simplified model of naturally relevant organic O/N-donor ligands.
A series of single crystals of [AnIV(Lp)2] complexes were synthesized from the tetrachloride compounds of An = Th, U and Np. SC-XRD measurements on the obtained crystals reveal their crystal structures, all showing the eight-fold coordination of the metal centre with the ligands on their primary coordination sphere, forming a trigonal dodecahedral geometry around the metal centre.
1H-NMR spectra of the dissolved complexes [ThIV(Le)2], [UIV(Le)2], [CeIV(Le)2] and the pure ligand in solution were recorded. The observed shifts show unique features when comparing isostructural diamagnetic compounds of lanthanides and actinides, which can not be explained by charge density differences.

  • Lecture (Conference)
    ISNSC - 10th International Symposium on Nano and Supramolecular Chemistry 2018, 10.07.2018, Dresden, Deutschland

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Publ.-Id: 28270