Jump to main content
Jump to site search

Issue 41, 2008
Previous Article Next Article

Symmetry-dependent solvation of donor-substituted triarylboranes

Author affiliations

Abstract

Donor-substituted triarylboranes are investigated by femtosecond absorption spectroscopy to study the influence of molecular symmetry on solvation. In solvents of varying polarity and differently fast solvation response, the solvation dynamics of a highly symmetric triple carbazole-substituted triarylborane (TCB) is compared to a single carbazole-substituted triarylborane (CB). The decomposition of the transient absorption spectra allows us to measure the solvation time by means of the time-dependent solvatochromic shift of the excited-state absorption (ESA) and the stimulated emission (SE). For all polar solvents under study we find an accelerated solvation process for TCB compared to the less symmetric CB. The difference is particularly large for solvents with a slow response. In order to explain these findings we propose that the electronic excitation is mobile in the symmetric molecule and can change between the three carbazole chromophores probably by a hopping mechanism. The excited-state dipole moment of TCB can thereby respond to the solvent relaxation and changes its direction according to the local field of the solvation shell. Thus, in a symmetric solute the possibility of an intramolecular charge delocalization over equivalent sites accelerates the approach of the minimum-energy configuration.

Graphical abstract: Symmetry-dependent solvation of donor-substituted triarylboranes

Back to tab navigation

Article information


Submitted
11 Apr 2008
Accepted
03 Jul 2008
First published
09 Sep 2008

Phys. Chem. Chem. Phys., 2008,10, 6245-6251
Article type
Paper

Symmetry-dependent solvation of donor-substituted triarylboranes

U. Megerle, F. Selmaier, C. Lambert, E. Riedle and S. Lochbrunner, Phys. Chem. Chem. Phys., 2008, 10, 6245
DOI: 10.1039/B806131A

Social activity

Search articles by author

Spotlight

Advertisements