Low-frequency Raman scattering of aqueous solutions of <i>L</i>-xyloascorbic acid and <i>D</i>-araboascorbic acid

Abstract

Depolarized low-frequency Raman spectra of aqueous solutions of L-xyloascorbic acid and its epimer D-araboascorbic acid have been investigated as a function of concentration at 30 °C. The influence of fluorescence in the low-frequency Raman spectral intensity of D-araboascorbic acid aqueous solution was removed by the background correction. The reduced χ″(ν̄) spectrum, which corresponds to the imaginary part of the dynamical susceptibility due to the dynamical structure of water in aqueous solutions, was analyzed with the superposition of one Cole–Cole type relaxation mode and two damped harmonic oscillator modes. The effect of L-xyloascorbic acid on the dynamical structure of water is less than that of D-araboascorbic acid.