Organic–inorganic hybrid polymers containing 3,4-ethylenedioxythiophene and chalcogens in the main chain

Abstract

A series of new organic–inorganic hybrid polymers containing 3,4-ethylenedioxythiophene (EDOT) along with mono- and di-chalogenides in the main chain were synthesized, characterized and their electrochemical and optical properties were investigated. It was found that the introduction of electron rich chalcogenide atoms on the EDOT ring lowers the oxidation potential of the monomer as compared to that of EDOT. Cyclic voltammogram studies on the PBEDOT-S2 revealed that it behaves effectively as a thia capped bis-EDOT moiety. It was also observed that the conductance of the dichalcogenide containing polymer was found to be lower than those of the corresponding monochalcogenide analogues. Spectroelectrochemical investigations revealed that these chalcogenide containing hybrid polymers exhibit transparent yellow color in the reduced state and are opaque blue in the oxidized state indicating their usefulness as anodically coloring materials in electrochromic devices. Furthermore, the polymer based on bis-3,4-ethylenedioxythiophene disulfide was found to exhibit a redox peak separation (ΔEp), which is the measure of redox kinetics, of 1.1 V making it a potential candidate for a solid redox polymer electrode material. Interestingly, this polymer exhibited the fastest disulfide redox kinetics on Pt electrode reported to date.