Dipole solvation in nondipolar solvents: Experimental studies of reorganization energies and solvation dynamics

Journal Article · Thu Jun 13 04:00:00 EDT 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp953110e· OSTI ID:374477

Reynolds, L; Gardecki, J A; Frankland, S J.V.; Horng, M L; Maroncelli, M ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

Steady-state and time-resolved emission measurements of the solvatochromic probe coumarin 153 are used to study solvation of a dipolar solute in nondipolar solvents such as benzene and 1,4-dioxane. Contrary to the predictions of dielectric continuum theories, the Stokes shifts (or nuclear reorganization energies) that accompany electronic excitation of this solute are substantial in such solvents (nearly 1000 cm{sup -1}). The magnitudes of the shifts observed in both nondipolar and dipolar solvents can be consistently understood in terms of the relative strength of the interactions between the permanent charge distributions of the solute and solvent molecules. (Information concerning these charge distributions is derived from extensive ab initio calculations on the solute and 31 common solvents). The dynamics of solvation in nondipolar solvents, as reflected in the time dependence of the Stokes shifts, is qualitatively like that observed in polar solvents. But, whereas the dynamics in polar solvents can be rather simply modeled using the solvents dielectric response as empirical input, no simple theories of this sort are currently capable of predicting the solvation dynamics in nondipolar solvents 52 refs., 14 figs., 4 tabs.

• OSTI ID: 374477
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 24 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
66 PHYSICS
ABSORPTION SPECTRA
CALCULATION METHODS
COUMARIN
DIPOLE MOMENTS
DISTRIBUTION
DYNAMICS
ELECTRIC CHARGES
EMISSION SPECTRA
MOLECULAR ORBITAL METHOD
SOLUTES
SOLVATION
SOLVENTS
STOKES PARAMETERS