Computational dielectric spectroscopy shows that water/methanol mixtures form hybrid hydrogen bonding networks

Abstract

Methanol/water mixtures are miscible across the entire composition range, despite having vastly different hydrogen bonding superstructures. The exact nature of the hydrogen bonding structure in these mixtures has been debated. Dielectric spectroscopy can be used to probe whether the collective reorientation of the hydrogen-bonding superstructure has timescales associated with methanol and water separately or a single relaxation, indicating a hybrid structure. Through analysis of the component spectra, we find only one relaxation accounting for all hydrogen-bonding structure reorientations across the entire composition range, indicating that a hybrid hydrogen bonding structure is indeed formed across that entire range.