Reactions of laser-ablated uranium atoms with H2O in excess argon: a matrix infrared and relativistic DFT investigation of uranium oxyhydrides.
Laser-ablated U atoms react with H2O during condensation in excess argon. Infrared absorptions at 1416.3, 1377.1, and 859.4 cm(-1) are assigned to symmetric H-U-H, antisymmetric H-U-H, and U=O stretching vibrations of the primary reaction product H(2)UO. Uranium monoxide, UO, also formed in the reaction, inserts into H2O to produce HUO(OH), which absorbs at 1370.5, 834.3, and 575.7 cm(-1). The HUO(OH) uranium(IV) product undergoes ultraviolet photoisomerization to a more stable H2UO2 uranium(VI) molecule, which absorbs at 1406.4 and 885.9 cm(-1). Several of these species, particularly H2UO2, appear to form weak Ar-coordinated complexes. The predicted vibrational frequencies, relative absorption intensities, and isotopic shifts from relativistic DFT calculations are in good agreement with observed spectra, which further supports the identification of novel uranium oxyhydrides from matrix infrared spectra.
Liang
Binyong
B
Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319, USA.
Hunt
Rodney D
RD
Kushto
Gary P
GP
Andrews
Lester
L
Li
Jun
J
Bursten
Bruce E
BE