The instructive redox behaviour of 4‐ferrocenylcatechol on nanocrystalline titanium dioxide electrodes |
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| Authors: | Felicia J D Maharaj Andrew M McDonagh Stephen B Colbran |
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| Institution: | 1. School of Chemistry, The University of New South Wales, Sydney, NSW 2052, Australia;2. Department of Chemistry, Materials and Forensics, University of Technology Sydney, Sydney, NSW 2007, Australia |
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| Abstract: | An investigation into the redox behaviour of 4‐ferrocenylcatechol bound to nanocrystalline TiO2 electrodes identified a limitation to the use of catechol as an electron‐transfer facilitating anchoring group. 4‐Ferrocenylcatechol was adsorbed to transparent nanocrystalline TiO2 electrodes. UV–visible spectra of the modified electrode were recorded in an acetonitrile‐electrolyte solution. At an applied potential of + 0.45 mV (vs Ag/AgCl/Cl?) the ferrocenyl group oxidized to the ferrocenium cation and the catecholate group oxidized to the benzoquinone form. Subsequent application of a potential of 0 V reduced the ferrocenium to ferrocene but, owing to the irreversibility of the catechol oxidation in aprotic solvents, benzoquinone is not reduced to catecholate and subsequently desorbs and is lost due into solution. Electrochromic switching of the ferrocenyl electrochromophore on TiO2 with aprotic electrolyte is, therefore, irreversible. Copyright © 2006 John Wiley & Sons, Ltd. |
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| Keywords: | titanium dioxide ferrocene catechol electrochemistry |
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