Molecular Dynamics Simulations on the Special System of TFE Aqueous Solution

Abstract

2,2,2-trifluoroethanol(TFE) aqueous solution is a special associate system. Molecular dynamics (MD) simulations combined with the chemical shifts in NMR were used to investigate the hydrogen-bond network in TFE-water system. The strong hydrogen bonds and weak C—H…O contacts were found existing in the TFE-water mixtures from the information of radial distribution function (RDF). And the TFE-water mixtures could be divided into three different regions from the analysis of the hydrogen-bonding network. In the water rich region, water molecules prefer to form the hydrogen bonds with themselves and establish the stable clusters. With the concentration of TFE increasing, the stable structure of water molecules was broken down. In the TFE rich region, the self-associated clusters of TFE were dominant. In addition, the chemical shifts were adopted to study the interactions in the mixtures. The varieties of the average hydrogen bond numbers from MD simulations and the chemical shifts in NMR showed good agreement.