Anna Sokołowska

Effect of LiCl and LiClO4 on vibration coupling and Fermi resonance in the Raman spectra of liquid water

Abstract The 3400 cm −1 region of the Raman spectrum of liquid water and of aqueous solutions of LiCl and LiClO 4 was investigated by analysing the isotropic and anisotropic components of the bands. Two resonances, Darling—Dennison ν 1 , ν 3 and Fermi ν 1 , 2ν 2 , interfere with each other and the interference is different in LiCl and LiClO 4 solutions. The Fermi coupling constant W was estimated to be 97 cm −1 in pure liquid water, i.e., nearly 3 times higher than in the vapour phase, and to decrease to about 70 cm −1 in the concentrated solutions of the studied salts.