Study of Molecules with Multiple Redox Centers Using Differential Staircase Voltammetry at Spherical Electrodes and Microelectrodes

Manuela López-Tenés, Carmen Serna, Marién M. Moreno, Ángela Molina*

Departamento de Química Física, Universidad de Murcia, Espinardo 30100, Murcia, Spain

 

Abstract

The study of the reversible reduction/oxidation molecules containing multiple interacting or noninteracting redox centers has been carried out using the multipotential step technique Differential Staircase Voltammetry (DSCV). Methods to obtain the formal potentials and other characteristic parameters of the process are proposed for any interaction degree between the centers, when using spherical electrodes of any size (from planar to ultramicrospherical electrodes) and, in particular, the advantages of microelectrodes are discussed. The theoretical predictions have been tested with two experimental systems: ethyl viologen in acetonitrile and pyrazine in aqueous acid media, finding an excellent agreement between the theory and experiments. Therefore, the formal potentials for these systems have been evaluated using DSCV.

Keywords: Multicenter molecules; interacting and noninteracting redox centers; multipotential techniques; Differential Staircase Voltammetry; DSCV; spherical electrodes; microelectrodes

 

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* Corresponding author. E-mail address: amolina@um.es