12036-71-4Relevant articles and documents
Reactions of pulsed-laser evaporated uranium atoms with molecular oxygen: Infrared spectra of UO, UO2, UO3, UO2+, UO22+, and UO3-O2 in solid argon
Hunt, Rodney D.,Andrews, Lester
, p. 3690 - 3696 (2007/10/02)
Uranium atoms from the Nd:YAG laser ablation of a uranium target were codeposited with molecular oxygen and excess argon at 12 K.Infrared spectra following the U + O2 reaction revealed a wide range of reaction products.The 776.0 cm-1 band due to UO2 was the strongest product absorption, strong UO3 bands were observed at 852.5 and 745.5 cm-1, and a weak UO absorption appeared at 819.8 cm-1.These product absorptions are in agreemet with earlier work, which evaporated UO2 from a tungsten Knudsen cell at 2000 deg C.The 16O2/18O2 reaction gave only U 16O2 and U 18O2, which verified an insertion mechanism.New product absorptions were observed at 952.3, 892.3, and 842.4 cm-1.The 842.4 cm-1 absorption due to the UO3-O2 complex and the 892.3 cm-1 band assigned to the charge-transfer complex (UO2+)(O2-) grew markedly at the expense of the other uranium oxides during annealing the matrix to allow diffusion and reaction of O2.With 25percent 16O2, 50percent 16O18O, and 25percent 18O2 samples, the 952.3 cm-1 and became a sharp triplet at 952.3, 936.5, and 904.5 cm-1 and exhibited an isotopic ratio appropriate for a linear OUO species.Agreement of this bond with uranyl ion spectra suggests assignment to a (UO22+) complex.Mechanisms of formation of charged species are discussed.
