Dynamical and structural properties of monohydroxy alcohols exhibiting a Debye process

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Materials Science

Background:

• Understanding the dynamical and structural properties of primary monohydroxy alcohols is crucial for various chemical and industrial applications.
• Previous studies suggest complex relaxation processes in alcohols, but the precise mechanisms remain under investigation.

Purpose of the Study:

• To investigate the dynamical and structural properties of primary monohydroxy alcohols using molecular dynamics simulations.
• To elucidate the relationship between molecular dynamics, hydrogen bonding, and observed relaxation processes.

Main Methods:

• Molecular dynamics simulations were employed to model primary monohydroxy alcohols.
• Rotational correlation functions were analyzed for individual and total dipole moments.
• Cluster analysis was used to identify hydrogen-bonded structures.
• A novel algorithm tracked the time evolution of transient hydrogen-bonded chains.

Main Results:

• Simulations revealed a Debye process slower than the alpha process, consistent with experimental findings.
• Hydroxyl groups form transient, chain-like hydrogen-bonded aggregates.
• The lifetimes of these transient chains are shorter than the Debye process correlation times.
• Orientational correlations extend beyond hydrogen-bonded chains due to induced dipole fields.

Conclusions:

• The Debye relaxation process in primary monohydroxy alcohols is not a direct consequence of transient hydrogen-bonded chain reorganization.
• Dipole fields exerted by hydrogen-bonded chains influence the orientation of neighboring molecules.
• The findings support a La-Ola wave model with diffusive propagation to explain the observed dynamics.