Electrosynthesis and Characterisation of Poly(3,4-Ethylenedioxythiophene) Films Incorporating Ferrocene

Abstract

Poly(3,4-ethylenedioxythiophene) (PEDOT) films were potentiostatically and potentiodynamically prepared on Pt electrodes from acetonitrile monomer solutions containing TBAPF 6 or FcPF 6 (or both). The polymer modified electrodes obtained with different growth charges were characterized electrochemically by cyclic voltammetry in a monomer free solution. The results point to the effective immobilization of the ferrocenium ion inside the PEDOT matrix by entrapment during the polymer synthesis in potentiostatic mode. It is discussed the influence of the presence of the organometallic cation in the polymerization solution in the growth process and the efectiveness of the incorporation of the metallocene is analysed on the basis of the electrochemical data collected for the films redox conversion.Keywords: conducting polymers, ferrocene, immobilization. IntroductionMetallocenes are characterised for exhibiting properties that allow their use as catalysts (e.g., reduction of ketones, olefins polymerization) in homogeneous [1] and heterogeneous [2] conditions, justifying the intense investigation in view of their potential applications in many areas such as electrocatalysis [3] and biosensors [4]. The immobilisation of such metallocomplexes in a suitable solid support presents as major advantages the fact of not having restrictions on the solubility of the catalyst, its low losses and facile separation from reaction products [5]. From the most noteworthy materials used for the metallic centre incorporation we can distinguish inert matrices such as silica [2] or polymeric resins [6], and electroactive supports such as electronically conducting polymers (ECPs) [7][8][9][10][11][12][13], being the latter route the approach followed in the present work. Compared with