Dynamical Structure of Water in Aqueous Solutions of Ascorbic Acid by Low-Frequency Raman Scattering

Abstract

Depolarized low-frequency Raman spectra of aqueous solutions of L-ascorbic acid and its isomer D-araboascorbic acid as a function of concentration have been investigated in the frequency region from −250 cm⁻¹ to 250 cm⁻¹ at 30°C. The reduced χ″(\barν) 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-ascorbic acid on the dynamical structure of water is different from the effect of D-araboascorbic acid.