Low-frequency Raman scattering study of tert-butyl alcohol–water and tetrahydrofuran–water binary mixtures

Abstract

Low-frequency Raman scattering spectra have been measured for tert-butyl alcohol (TBA)–water and tetrahydrofuran (THF)–water binary mixtures as a function of concentration. We confirmed the isosbestic point in the reduced Raman spectra χ″(ν) of the TBA–water and THF–water mixtures. The χ″(ν) spectra could be decomposed into a linear combination of the neat TBA spectrum and the pure water spectrum in the frequency range from 80 to 400 cm−1. On the other hand, below 80 cm−1, the χ″(ν) spectra could not be decomposed into a linear combination. The superposed spectra deviated systematically from the experimental spectra as a function of solute concentration. This result indicated that cooperative dynamics was present in TBA–water and THF–water mixtures although the intermolecular vibrations showed independent character.