FTIR spectra of the hydrolysis of uranium hexafluoride

Abstract

The hydrolysis of uranium hexafluoride has been examined with infrared spectroscopy under three different reaction conditions. First, UF{sub 6} was codeposited with water in excess argon at 12 K. The FTIR spectra of UF{sub 6}/H{sub 2}O mixtures revealed several product absorptions due to the perturbed v{sub 1}, v{sub 2}, and v{sub 3} modes of H{sub 2}O as well as the v{sub 3} mode of UF{sub 6}. These new absorptions have been assigned to the anti-hydrogen-bonded 1:1 complex, UF{sub 6}-OH{sub 2}. Photolysis of this weak complex produced a doublet at 868.2 and 857.1 cm{sup -1}, which has been assigned to the UOF{sub 4}. Next, solid films of UF{sub 6}/H{sub 2}O mixtures were prepared at 12 K and slowly annealed at 242 K. The reaction profile of the UF{sub 6} hydrolysis from UF{sub 6} hydrolysis from UF{sub 6} (or UF{sub 6}-OH{sub 2}) to UOF{sub 4} to UO{sub 2}F{sub 2} was obtained. Finally, UF{sub 6} and H{sub 2}O were reacted at low pressures and ambient temperatures in a new IR gas cell. While no gaseous uranium oxyfluorides were detected, the final product distribution inside the gas cell did indicate that the fluorinated nickel surface served as a catalyst for the UF{sub 6} hydrolysis.more » 21 refs., 4 figs., 1 tab.« less