211239-38-2Relevant articles and documents
Electron transfer in mixed-valence polyferrocenium cations: Preparation, electrochemistry, and 57Fe M?ssbauer characteristics
Dong, Teng-Yuan,Lee, Wen-Yu,Su, Pau-Tang,Chang, Ling-Shao,Lin, Kuan-Jiuh
, p. 3323 - 3330 (1998)
Convenient new methods are developed for the preparation of 1′,1″?-disubstituted triferrocenes and tetraferrocenes that can be oxidized with iodine to a new series of mixed-valence compounds. The X-ray structures of 1′,1″?-diethyltriferrocene, 1′,1″?-dimethoxymethyltriferrocene, and 1′,1″?-dimethoxymethyltetraferrocene have been determined at 298 K. The rates of intramolecular electron transfer in these mixed-valence cations were estimated by variable-temperature 57Fe M?ssbauer experiments. The features in all 80 and 300 K spectra include two doublets, one with a quadrupole splitting (ΔEQ) of ~2 mm s-1 (Fe(II) site) and the other with ΔEQ = ~0.3 mm s-1 (Fe(III) site). This pattern of two doublets is expected for a mixed-valence biferrocenium cation that is valence-trapped on the time scale of the M?ssbauer technique (electron-transfer rate 7 s-1 in the solid state). The electrochemical measurements are also presented.