Infrared Investigation of Uranyl Chloride and Uranyl Fluoride

Abstract

In many uranyl compounds the most often literature found is for the fundamental vibrations of the uranyl ion while there is negligible literature on the anion vibrations which mostly fall in the far-IR region. The crystal structure studies of many uranyl compounds have shown the UO₂ bond as being almost linear. In the present study of UO₂Cl₂ and UO₂F₂ theUO₂ bond is assumed to be very nearly linear and belonging to the C_2v point group of symmetry. A normal coordinate analysis has confirmed the linear configuration of theUO₂ for the two molecules. A complete vibrational assignment of the anion vibrational modes in the IR spectra is well supported by high values of the potential energy distribution calculated from the force constants.