Structural properties of aqueous mixtures of monohydric alcohols from near-infrared absorption spectra

Abstract The 1450 nm band of water, usually assigned to ν 1 + ν 3 (ν 1 is the symmetric stretching and ν 3 the asymmetric stretching mode), has been measured in aqueous methanol, ethanol and 2-propanol solutions as a function of alcohol concentration over the entire cosolvent mole fraction region. For all systems investigated, the near-infrared absorption coefficient exhibits an anomalous behaviour which occurs in the water-rich region (mole fraction of cosolvent χ 2 2 *, for which there is a change in the nature of the interactions in solution.