Scientific Achievement

Tris(carbene) donors (C3) are introduced as a new all-carbon donor ligand set for f-block cations. They bind primarily through sigma donation, providing a contrast to other organolanthanide complexes, and are more thermally and oxidatively stable, and more covalent, than the common tris(pyrazolyl)borate analogue.

Significance and Impact

This new class of compounds expands the range of molecules that we can use to study the f-electron challenge. Significant differences between early and late lanthanide C3 complexes suggest potential use in rare earth separations, and guide the design of new complexes for applications in catalysis, materials science, and magnetism.

Research Details

  • Cerium forms a neutral complex with the tris(carbene) (Ce(C3)2I), while ytterbium forms a separated ion pair [Yb(C3)2]I resulting in a difference in solubility of the two species in thf
  • The C3 ligand showed a preference for higher oxidation state metal complexes compared to the tris(pyrazolyl) Tp* ligand
  • DFT/QTAIM computational analysis highlighted greater covalency in metal-carbon bonds of C3 complexes
  • Including THF solvent in calculations is essential to reproduce the contrasting geometries for Ce and Yb complexes

Publication Details

A. Price, A. Gupta, W. de Jong, P. L. Arnold. Dalton Trans., 2023.
DOI: 10.1039/D3DT00718A10.1039/D3DT00718A