1,1鈥?Biferrocenylenes鈥擳he More Redox Stable Ferrocenes! New Derivatives, Corrected NMR Assignments, Redox Behavior, and Spectroelectrochemistry
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- 作者：Rochus Breuer ; Michael Schmittel
- 刊名：Organometallics
- 出版年：2012
- 出版时间：March 12, 2012
- 年：2012
- 卷：31
- 期：5
- 页码：1870-1878
- 全文大小：376K
- 年卷期：v.31,no.5(March 12, 2012)
- ISSN：1520-6041
文摘
Following an improved protocol, several monosubstituted 1,1鈥?biferrocenylenes (BFDs) were prepared as a mixture of 伪 and 尾 constitutional isomers. The isomers were separated and their structures assigned from 1H鈥?sup>1H-COSY and 1H鈥?sup>1H-ROESY NMR data, resulting in a correction of earlier erroneous assignments. Both redox stages (BFD0/BFD+ and BFD+/BFD2+) were examined by cyclic voltammetry. The reactivity of the parent BFD+ versus that of ferrocenium (Fc+) in aqueous solution was evaluated by UV鈥搗is spectroscopy, suggesting that ferrocene should be replaced by BFD derivatives for redox applications in aqueous media due to their more than 1000-fold higher kinetic stability. Electronic transitions of monoalkylated BFD+ derivatives were measured by thin-layer spectroelectrochemistry, revealing unperturbed mixed-valence class III systems independent of 伪 or 尾 substitution.