Homoleptic Aryl Complexes of Uranium (IV)

The synthesis and characterization of sterically unencumbered homoleptic organouranium aryl complexes containing U-C sigma-bonds has been of interest to the chemical community for over 70 years. Reported herein are the first structurally characterized, sterically unencumbered homoleptic uranium (IV) aryl-ate species of the form [U(Ar)(6)](2-) (Ar=Ph, p-tolyl, p-Cl-Ph). Magnetic circular dichroism (MCD) spectroscopy and computational studies provide insight into electronic structure and bonding interactions in the U-C sigma-bond across this series of complexes. Overall, these studies solve a decades-long challenge in synthetic uranium chemistry, enabling new insight into electronic structure and bonding in organouranium complexes.