Purely mechanical solvation dynamics in supercooled liquids

The S0 ← T1 (0-0) transition of naphthalene

Hauke Wendt, Ranko Richert

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

We have measured the Stokes shift and its dynamics for the probe molecules naphthalene (Δμ ≈ 0) and quinoxaline (Δμ ≈ 1.3 D) in n-propanol and other glass-forming solvents. The Stokes shift for naphthalene (≈63 cm-1) turns out to be independent of the solvent polarity over a wide range of the static dielectric constants. Its time dependence is governed by the structural (or α- or shear stress) relaxation time of n-propanol, without any signature of the strong dielectric relaxation. For this solvent, structural and dipolar contributions can be distinguished because the time scale for dipole reorientation is a factor of 25 slower than the α-relaxation time. We conclude that the solvation of naphthalene reflects excitation-induced changes in the van der Waals interactions, which makes it an ideal probe for assessing shear stress or mechanical relaxations on microscopic spatial scales near Tg.

Original languageEnglish (US)
Pages (from-to)5775-5781
Number of pages7
JournalJournal of Physical Chemistry A
Volume102
Issue number29
StatePublished - Jul 16 1998
Externally publishedYes

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Solvation
naphthalene
solvation
1-Propanol
stress relaxation
Stress relaxation
Relaxation time
shear stress
Shear stress
Liquids
liquids
relaxation time
Anelastic relaxation
quinoxalines
Quinoxalines
probes
Dielectric relaxation
shift
retraining
time dependence

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Purely mechanical solvation dynamics in supercooled liquids : The S0 ← T1 (0-0) transition of naphthalene. / Wendt, Hauke; Richert, Ranko.

In: Journal of Physical Chemistry A, Vol. 102, No. 29, 16.07.1998, p. 5775-5781.

Research output: Contribution to journalArticle

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