Electrode Reaction of Cyclodextrin Complexes—Effect of β-Cydodextrin on the Electron-Transfer of Ferrocenecarboxylic Acid—

The effect of β-cyclodextrin (β-CyD) on the electron-transfer rates between glassy carbon and ferrocenecarboxylic acid (FCA) has been investigated. The induced circular-dichroism spectrum shows that FCA can be included in β-CyD and the Fe atom in FCA is located in the cavity. Although the complexation retards the electron-transfer rate, the retardation effect of β-CyD is small, indicating that electrons can easily penetrate into the molecular wall of β-CyD. This result may be extended to other systems. Thus the retardation effect by addition of CyD is concluded not to be responsible for relatively large potential shifts, which are observed, for example, in the eiectroreduction of p-nitrophenol.