Local dielectric response in 1-propanol: $\alpha$-relaxation versus relaxation of mesoscale structures

Abstract

The dielectric Debye relaxation in monohydroxy alcohols has been subject of long-standing scientific interest and is presently believed to arise from the relaxation of transiently H-bonded supramolecular structures. Therefore, its manifestation might be expected to differ from a local dielectric probe as compared to the standard macroscopic dielectric experiment. In this work we present such local dielectric measurements obtained by triplet state solvation dynamics (TSD) and compare the results with macroscopic dielectric and light scattering data. In particular, with data from an improved TSD setup, a detailed quantitative comparison reveals that the Debye process does not significantly contribute to the local Stokes shift response function, while $\alpha$- and $\beta$-relaxations are clearly resolved. Furthermore, this comparison reveals that the structural relaxation has almost identical time constants and shape parameters in all three measurement techniques. Altogether our findings support the notion that the transiently bound chain structures lead to a strong cross-correlation contribution in macroscopic dielectric experiments, to which both light scattering and TSD are insensitive, the latter due to its local character and the former due to the molecular optical anisotropy being largely independent of the OH bonded suprastructures.

arXiv comment8 pages, 9 figures

References in corpus (5)

• Nuclear magnetic resonance measurements reveal the origin of the Debye process in monohydroxy alcohols
• Susceptibility functions for slow relaxation processes in supercooled liquids and the search for universal relaxation patterns
• Short-chain polymer rigidity due to the Debye process of monohydroxy alcohols
• Debye relaxation and 250 K anomaly in glass forming monohydroxy alcohols
• On the Nature of the Debye-Process in Monohydroxy Alcohols: 5-Methyl-2-Hexanol Investigated by Depolarized Light Scattering and Dielectric Spectroscopy

Cited by in corpus (5)

• Universal Structural Relaxation in Supercooled Liquids
• Intermolecular Cross-Correlations in the Dielectric Response of Glycerol
• The Influence of Molecular Architecture on the Dynamics of H-Bonded Supramolecular Structures in Phenyl-Propanols
• Molecular dynamics insights into the Debye process of 1-propanol
• Computing dielectric spectra in molecular dynamics simulations: using a cavity to disentangle self and cross correlations