On the Perturbation of the H-Bonding Interaction in Ethylene Glycol Clusters upon Hydration

Ab initio and density functional methods have been employed to study the structure, stability, and spectral properties of various ethylene glycol (EG<i>_m</i>) and ethylene glycol–water (EG_<i>m</i>W_<i>n</i>) (<i>m</i> = 1–3, <i>n</i> = 1–4) clusters. The effective fragment potential (EFP) approach was used to explore various possible EG_<i>m</i>W_<i>n</i> clusters. Calculated interaction energies of EG_<i>m</i>W_<i>n</i> clusters confirm that the hydrogen-bonding interaction between EG molecules is perturbed by the presence of water molecules and vice versa. Further, energy decomposition analysis shows that both electrostatic and polarization interactions predominantly contribute to the stability of these clusters. It was found from the same analysis that ethylene glycol–water interaction is predominant over the ethylene glycol–ethylene glycol and water–water interactions. Overall, the results clearly illustrate that the presence of water disrupts the ethylene glycol–ethylene glycol hydrogen bonds