Au as a Surrogate for F: The Case of UAu6 vs UF6

Here, anion photoelectron spectroscopy and first-principles quantum chemistry are used to demonstrate to what degree Au can act as a surrogate for F in UF6 and its anion. Unlike UF6, UAu6 exhibits strong ligand-ligand, i.e., Au-Au, interactions, resulting in three low-lying isomers, two of which are three-dimensional while the third isomer has a ring-like quasi twodimensional structure. Additionally, all the UAu6 isomers have open-shell electrons, which in nearly all cases are localized on the central U atom. The adiabatic electron affinity and vertical detachment energy are measured to be 3.05 +/- 0.05 and 3.28 +/- 0.05 eV, respectively, and are in very good agreement with calculations.

Automated summary

Anion photoelectron spectroscopy and first-principles quantum chemistry are used to demonstrate the substitution of F in UF6 with Au. UAu6 exhibits strong Au-Au interactions, leading to three low-lying isomers. All the UAu6 isomers have open-shell electrons localized on the central U atom. The measured adiabatic electron affinity and vertical detachment energy are in good agreement with calculations.