Revisiting the Aqueous Solutions of Dimethyl Sulfoxide by Spectroscopy in the Mid- and Near-Infrared: Experiments and Car-Parrinello Simulations.
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 DMSO-water 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.
School of Engineering, University of Aberdeen , Fraser Noble Building, Aberdeen AB24 3UE, United Kingdom.
Victoria M
VM
Wallace
Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
Nilesh R
NR
Dhumal
Technische Thermodynamik, Universität Bremen , Badgasteiner Str. 1, 28359 Bremen, Germany.
Florian M
FM
Zehentbauer
Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.|School of Computational Sciences, Korea Institute for Advanced Study , Seoul 130-722, Korea.
Hyung J
HJ
Kim
School of Engineering, University of Aberdeen , Fraser Noble Building, Aberdeen AB24 3UE, United Kingdom.|Technische Thermodynamik, Universität Bremen , Badgasteiner Str. 1, 28359 Bremen, Germany.|Erlangen School of Advanced Optical Technologies (SAOT), Universität Erlangen-Nürnberg , Erlangen, Germany.
Johannes
J
Kiefer
D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D014867:Water / Q000737:chemistry
D012996:Solutions; D014867:Water; D004121:Dimethyl Sulfoxide