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
α- and β-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.Comment: 8 pages, 9 figure