Activation of Gas-Phase Uranyl: From an Oxo to a Nitrido Complex
Résumé
The uranyl moiety, UO22+, is ubiquitous in the chemistry of
uranium, the most prevalent actinide. Replacing the strong uranium−oxygen
bonds in uranyl with other ligands is very challenging, having met with only
limited success. We report here uranyl oxo bond activation in the gas phase to
form a terminal nitrido complex, a previously elusive transformation. Collision
induced dissociation of gas-phase UO2(NCO)Cl2− in an ion trap produced the
nitrido oxo complex, NUOCl2−, and CO2. NUOCl2− was computed by DFT to
have Cs symmetry and a singlet ground state. The computed bond length and
order indicate a triple U−N bond. Endothermic activation of UO2(NCO)Cl2−
to produce NUOCl2− and neutral CO2 was computed to be thermodynami-
cally more favorable than NCO ligand loss. Complete reaction pathways for the CO2 elimination process were computed at the DFT level.