Pronounced effects of zero-point energy difference on intramolecular electron transfer in asymmetric mixed-valence biferrocenium cations: Structural, EPR, and 57Fe Mössbauer characteristics
Journal
Organometallics
Journal Volume
21
Journal Issue
20
Pages
4192-4200
Date Issued
2002
Author(s)
Abstract
The X-ray structural determinations of a series of asymmetric mixed-valence biferrocenium cations have been determined. The observations of the structural characteristics of the series of mixed-valence biferrocenium cations are also consistent with our Mössbauer studies. The features in the Mössbauer spectra of the asymmetric biferrocenium salts include two doublets, one with a quadrupole splitting of 1.5−2.2 mms-1 (Fe(II) site) and the other with a quadrupole splitting of 0.7−0.5 mms-1 (Fe(III) site). This pattern of two doublets is expected for a mixed-valence biferrocenium cation, which is valence-trapped on the time scale of the Mössbauer technique. Our data indicate that the zero-point energy difference plays a crucial role in determining the nature of the intramolecular electron-transfer rate. The electrochemical measurements and the EPR data are also described.
SDGs
Type
journal article