Synthesis of imido analogs of the uranyl ion

Here we describe the synthesis of two imido analogs of the uranyl ion, UO22+, in which the oxygens are replaced by divalent alkyi or aryl nitrogen groups: U((NBu)-Bu-t)(2)I-2(THF)(2) (1) and U(NPh)(2)I-2(THF)(3) (2) (where Bu-t is tert-butyl and THF is tetrahydrofuran). Both compounds have been fully characterized by standard analytical techniques, including x-ray crystallography, and the chemical bonding between the metal center and the nitrogen ligands was quantified by using hybrid density functional theory calculations. As expected for a uranyl analog, these complexes exhibit linear N-U-N linkages and very short U-N bonds. In addition, the theoretical calculations show strong involvement of the 5f and 6d electrons in the U-N bonding.