Relationship between Nanoscale Supramolecular Structure, Effectiveness of Hydrogen Bonds, and Appearance of Debye Process

Infrared and dielectric spectroscopy, X-ray diffraction, and density functional theory computations have been used to study the hydrogen-bonding pattern, molecular dynamics, internal structure, and dipole moment distribution in 2-ethyl-1-hexanol, 2-ethyl-1-hexylamine, 2-ethyl-1-hexanethiol, and 1-phenyl-2-butanol. Dielectric investigations revealed that Kirkwood–Frohlich correlation factor is much larger or lower than the unity in the vicinity of the glass transition, dependent on the compound. It indicates that change in the functionality of the H-bonding moiety influences the architecture of the supramolecular nanoassemblies. Further thorough experimental and theoretical considerations confirmed this hypothesis. Moreover, it was found that not the strength of hydrogen bonds itself, but the diverse population of nanoassociates, their size, and the spatial organization of the molecules in clusters have a strong influence on the appearance/absence as well as the intensity of the Debye relaxation. The resul...