Ethylene glycol revisited: Molecular dynamics simulations and visualization of the liquid and its hydrogen-bond network

Abstract

Molecular dynamics simulations of liquid ethylene glycol described by the OPLS-AA force field were performed to gain insight into its hydrogen-bond structure. We use the population correlation function as a statistical measure for the hydrogen-bond lifetime. In an attempt to understand the complicated hydrogen-bonding, we developed new molecular visualization tools within the Vish Visualization shell and used it to visualize the life of each individual hydrogen-bond. With this tool hydrogen-bond formation and breaking as well as clustering and chain formation in hydrogen-bonded liquids can be observed directly. Liquid ethylene glycol at room temperature does not show significant clustering or chain building. The hydrogen-bonds break often due to the rotational and vibrational motions of the molecules leading to an H-bond half-life time of approximately 1.5 ps. However, most of the H-bonds are reformed again so that after 50 ps only 40% of these H-bonds are irreversibly broken due to diffusional motion. This hydrogen-bond half-life time due to diffusional motion is 80.3 ps. The work was preceded by a careful check of various OPLS-based force fields used in the literature. It was found that they lead to quite different angular and H-bond distributions.

Molecular dynamics simulation of the hydration structure and hydrogen bonding behavior of phenol in aqueous solution

“…In particular, the aqueous binary mixtures of amphiphilic molecules, which contain both hydrophilic and hydrophobic groups, exhibit non-ideal properties and are proven to be important in chemistry. Thus considerable efforts have been devoted to investigate the micro-structure and intermolecular interaction of the binary aqueous mixtures [4][5][6] . The existing knowledge advances the present study to make a further exploration on the binary aqueous mixture of amphiphilic molecules.…”

A Symmetric Recognition Motif between Vicinal Diols: The Fourfold Grip in Ethylene Glycol Dimer

“…Indeed, the solid and liquid states of ethylene glycol are known or believed to form extended intermolecular networks 4, 29, 30, 39, 40. Furthermore, we are not aware of any report of this motif in crystal packings of carbohydrates, which usually prefer less strained infinite cooperative chains 41, 42.…”

Zero-field nuclear magnetic resonance spectroscopy of viscous liquids

“…Molecular-dynamics simulations would be able, in principle, to provide the full distribution of dihedral angles of EG. However, currently available classical force fields are not sufficiently accurate to describe hydrogen bonds and the associated key dihedral angles involving the OH groups (indeed, there is no generally accepted parameterization even of the OCCO angle [30,42,43]). On the other hand, Car-Parrinello simulations [44] are too demanding for the slow dynamics of a viscous fluid.…”