E. Coutouli-argyropoulou, A. Kelaidopoulou, C. Sideris
Nov 22, 1999
Citations
0
Influential Citations
33
Citations
Journal
Journal of Electroanalytical Chemistry
Abstract
The voltammetric behaviour of (ferrocenylmethyl)trimethylammonium hexafluorophosphate, 2-ferrocenylacrylic acid, N-ferrocenylmethyl-N′-methyl-4,4′-bipyridinium hexafluorophosphate and 9-ferrocenylmethyladenine was studied in aqueous and/or acetonitrile solutions by means of cyclic voltammetry and rotating-disc electrode voltammetry. The influence of β-cyclodextrin on the voltammetric behaviour of the compounds was also studied in aqueous solutions. (Ferrocenylmethyl)trimethylammonium hexafluorophosphate and 2-ferrocenylacrylic acid, studied in aqueous solutions at pH 9.2, exhibit typical reversible one electron transfer behaviour, whereas the redox reaction of 9-ferrocenylmethyladenine, studied in acetonitrile, is strongly affected by adsorption. N-ferrocenylmethyl-N′-methyl-4,4′-bipyridinium hexafluorophosphate gives voltammetric responses for both ferrocene and viologen redox centres in acetonitrile. In aqueous solutions it is hydrolyzed to ferrocenylmethylalcohol and N-methylbipyridyl, a process facilitated by the neighbouring group participation of the iron atom. In all cases β-cyclodextrin causes a decrease in the currents and shifts the potentials positively. The formation constants of the inclusion complexes of compounds with β-cyclodextrin were determined by quantitative evaluation of E1/2 values and possible explanations about their differentiation are discussed. In the case of N-ferrocenylmethyl-N′-methyl-4,4′-bipyridinium hexafluorophosphate it was found that β-cyclodextrin decreases the rate of its hydrolysis substantially.