Raman spectroscopic study of the uranyl oxyhydroxide hydrates: becquerelite, billietite, curite, schoepite and vandendriesscheite

Raman and infrared spectra of five uranyl oxyhydroxide hydrates, becquerelite, billietite, curite, schoepite and vandendriesscheite, are reported. The observed bands are attributed to the (UO2)(2+) stretching and bending vibrations, U-OH bending vibrations and H2O and (OH)(-) stretching, bending and libration modes. The U-O bond lengths in uranyls and the O-H center dot center dot center dot O bond lengths are calculated from the wavenumbers assigned to the stretching vibrations. They are close to the values inferred and/or predicted from the X-ray single-crystal structure. The complex hydrogen-bonding network arrangement was proved in the structures of all the minerals studied. This hydrogen bonding contributes to the stability of these uranyl minerals. Copyright (c) 2006 John Wiley & Sons, Ltd.