UNIGE document Scientific Article
previous document  unige:2945  next document
add to browser collection
Title

Direct Investigation of the Dynamics of Charge Recombination Following the Fluorescence Quenching of 9,10-Dicyanoanthracene by Various Electron Donors in Acetonitrile

Authors
Hoegemann, Claudia
Allonas, X.
Published in Journal of Physical Chemistry. A. 1998, vol. 102, no. 38, p. 7362-7369
Abstract The dynamics of the intermediate generated upon diffusional electron transfer (ET) quenching of 9,10-dicyanoanthracene by electron donors of varying oxidation potential in acetonitrile has been investigated using several transient grating techniques. With most of the donor/acceptor pairs studied, the transient grating spectrum cannot be differentiated from those of the free ions. Exciplex fluorescence, with the same lifetime as that of the ion pair, is observed with all donors. To extract from the measured kinetics the rate constant of exciplex dissociation,, and of back ET,, within these exciplexes, three different schemes have been considered. The best agreement is obtained by assuming that charge recombination predominantly takes place within the exciplex. The obtained values are substantially different from the BET rate constants deduced indirectly from the free-ion yields and with a donor-independent rate constant of separation. For each class of donors, exhibits a logarithmic free energy dependence with a slope of about −2 eV-1. Moreover, is not constant but increases continuously with diminishing donor's oxidation potential.
Identifiers
Full text
Structures
Research group Groupe Vauthey
Citation
(ISO format)
VAUTHEY, Eric, HOEGEMANN, Claudia, ALLONAS, X. Direct Investigation of the Dynamics of Charge Recombination Following the Fluorescence Quenching of 9,10-Dicyanoanthracene by Various Electron Donors in Acetonitrile. In: Journal of Physical Chemistry. A, 1998, vol. 102, n° 38, p. 7362-7369. https://archive-ouverte.unige.ch/unige:2945

212 hits

0 download

Update

Deposited on : 2009-09-21

Export document
Format :
Citation style :