Infrared spectra of UO2, UO2+, and UO2- in solid neon

Reactions of laser-ablated uranium atoms, cations, and electrons with O-2 d uring condensation with excess neon produce UO, UO2, UO3, UO2+, and UO2- as characterized by infrared spectra with oxygen isotopic substitution and B3 LYP/pseudopotential calculations. Differences in low-lying states for UO2 g ive rise to substantial shifts and ground state reversal between argon and neon matrices. A series of B3LYP/pseudopotential calculations has been unde rtaken on oxide species related to the uranyl dication by the addition of o ne, two, or three electrons. Several electronic states have been characteri zed for each species. These simple, low-cost calculations predict vibration al frequencies which match those observed in neon matrices extremely well ( typically 3-5% too high). The ground state of neutral UO2 appears to have ( 3)Phi(u), symmetry, while (2)Phi(u), ground states are implied for UO2+ and UO2-.