Revisiting the Aqueous Solutions of Dimethyl Sulfoxide by Spectroscopy in the Mid- and Near-Infrared: Experiments and Car-Parrinello Simulations

Victoria M. Wallace, Nilesh R. Dhumal, Florian M. Zehentbauer, Hyung J. Kim, Johannes Kiefer*

*Corresponding author for this work

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

The infrared and near-infrared spectra of the aqueous solutions of dimethyl sulfoxide are revisited. Experimental and computational vibrational spectra are analyzed and compared. The latter are determined as the Fourier transformation of the velocity autocorrelation function of data obtained from Car-Parrinello molecular dynamics simulations. The experimental absorption spectra are deconvolved, and the excess spectra are determined. The two-dimensional excess contour plot provides a means of visualizing and identifying spectral regions and concentration ranges exhibiting nonideal behavior. In the binary mixtures, the analysis of the SO stretching band provides a semiquantitative picture of the formation and dissociation of hydrogen-bonded DMSOwater complexes. A maximum concentration of these clusters is found in the equimolar mixture. At high DMSO concentration, the formation of rather stable 3DMSO:1water complexes is suggested. The formation of 1DMSO:2water clusters, in which the water oxygen atoms interact with the sulfoxide methyl groups, is proposed as a possible reason for the marked depression of the freezing temperature at the eutectic point.

Original languageEnglish
Pages (from-to)14780-14789
Number of pages10
JournalThe Journal of Physical Chemistry B
Volume119
Issue number46
Early online date28 Oct 2015
DOIs
Publication statusPublished - 19 Nov 2015

Keywords

  • MOLECULAR-DYNAMICS SIMULATION
  • HYDROGEN-BONDING INTERACTIONS
  • DENSITY-FUNCTIONAL THEORY
  • LIQUID WATER
  • COMPUTER-SIMULATION
  • IR SPECTROSCOPY
  • BINARY-MIXTURES
  • IONIC LIQUID
  • DMSO
  • HYDRATION

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