Hydrogen bonds and dynamics of liquid water and alcohols

Using modified Arrhenius approximations, the activation energies of water, alcohols, and hexane structure rearrangement reactions responsible for the temperature dependences of their dynamic and dielectric characteristics were determined. The interactions of van der Waals and charged centers of water and alcohol molecules regulate the translational and rotational motion of molecules, ensuring the coordination and balance of the thermal effects of exothermic and endothermic rearrangement reactions in local structure of hydrogen bonding network. The long-range action of fluctuating dipoles of hydrogen bonds and their resonant excitation by thermal energy underlies the anomalies in the temperature dependences of water properties and initiates its phase transitions at points 273 K and 298 K. The deviation of the molecular dynamics of water from the Arrhenius and Stokes-Einstein equations in the range of 273-298 K was associated with a high contribution of the collective dynamics of the ice-like phase of water consisting of a network of hydrogen bonds structured by hexagonal clusters of Ih-ice. (C) 2020 Elsevier B.V. All rights reserved.