Determination of heterogeneous electron-transfer kinetics of decamethylferrocene at low temperatures (120 K < T < 200 K) by a.c. impedance - Université de Bretagne Occidentale
Journal Articles Journal of electroanalytical chemistry and interfacial electrochemistry Year : 2006

Determination of heterogeneous electron-transfer kinetics of decamethylferrocene at low temperatures (120 K < T < 200 K) by a.c. impedance

Abstract

Low-temperature heterogeneous electron-transfer kinetics of decamethylferrocene obtained from a.c. impedance analysis are reported. The experiments have been performed for 120 K < T < 200 K with a gold working electrode in two different electrolyte solution mixtures containing equal amounts of decamethylferrocene and decamethylferricinium, tetrafluoroborate: 7:1:16 (v:v:v) tetrahydrofuran/2-methyltetrahydrofuran/ethylchloride with lithium tetrafluoroborate, and 1:2 (v:v) butyronitrile/ethylchloride with tetrabutylammonium perchlorate. Values of standard rate constants for each temperature have been evaluated by fitting the experimental a.c. impedance spectra with a simple RC parallel circuit in the middle frequency part of complex-plane plots. The analysis of Arrhenius plots, corrected from solvent dynamics (In k(0)T(1/2) vs T-1), for the range of temperatures studied yields the free activation energy Delta G* and the pre-exponential factor A' for the two solvents mixtures (respectively 18.22 kJ mol(-1) and 1140 cm s(-1) in the tetrahydrofuran-based solvent system, 22.53 U mol(-1) and 2618 cm s(-1) in the butyronitrile-based solvent system). The very slight discrepancies between the experimental results and theoretical values calculated from the solvent dielectric continuum model are discussed. (c) 2006 Elsevier B.V. All rights reserved.

Dates and versions

hal-01175775 , version 1 (12-07-2015)

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Cite

Nicolas Le Poul, Stephen J. Green, Yves Le Mest. Determination of heterogeneous electron-transfer kinetics of decamethylferrocene at low temperatures (120 K < T < 200 K) by a.c. impedance. Journal of electroanalytical chemistry and interfacial electrochemistry, 2006, 596 (1), pp.47--56. ⟨10.1016/j.jelechem.2006.07.005⟩. ⟨hal-01175775⟩
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