Raman spectra of water in rare earth chloride solutions

Raman data were obtained for both polarizations of the OD stretching vibrations of HDO in six or seven concentrations of aqueous solutions of LaCl3, GdCl3, and LuCl3 in which 5 mole% of the water was D2O. For comparison, data were also obtained for the OH stretching vibrations of HDO in GdCl3 which had 95 mole% deuterated water. The rare earth salt concentrations of these solutions were approximately 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5m. All of these data were taken at room temperature. Cation dependent effects were observed in the peak positions and half-widths of the water bands for high solution concentrations. A differential analysis technique was developed which allowed the identification of distributions of frequencies associated with water molecules which were clearly affected in different ways by the rare earth and chloride ions.