Hydrophilic Oligo(oxyethylene)-Derivatized Poly(3,4-ethylenedioxythiophenes):  Cation-Responsive Optoelectroelectrochemical Properties and Solid-State Chromism

Abstract

Electroactive π-conjugated polymers have been synthesized by electrochemical polymerization of precursors consisting of two (3,4-ethylenedioxythiophene) (EDOT) groups linked by oligo(oxyethylene) chains of variable length. The analysis of the cyclic voltammetric behavior in the presence of various cations (Bu4N+, Li+, Na+, Ca2+, Sr2+, and Ba2+) shows that the nature and charge of the electrolyte cation exert a considerable influence on the potential of the anodic peak associated with the oxidation of the polymer, with positive shifts of several hundreds of millivolts in the presence of doubly charged cations. Spectroelectrochemistry shows that complexation of metal cations by the polyether network induces conformational changes in the π-conjugated backbone, which significantly contributes to the observed increase of the oxidation potential and the band gap. The polymers exhibit a high hydrophilicity, and experiments performed in the presence of Ba2+ show that replacement of acetonitrile by water produces a ca. 500 mV negative shift of the oxidation peak accompanied with a 0.30 eV decrease of the band gap, which reaches a minimal value under these conditions. These phenomena indicative of an enhancement of the effective conjugation in the polymer backbone are attributed to the removal of Ba2+cations with concomitant swelling of the polymer by a specific solvation of the oligo(oxyethylene) network by water molecules. As a consequence of this high structural flexibility and environmental stability, the polymers exhibit fast, intense, and reversible ionochromic effects in the solid state.

Characterization of PEDOT film functionalized with a series of automated synthesis ferrocenyl-containing oligonucleotides

“…23 According to our previous results on PEDOT-based modified electrodes, 24 we describe here the synthesis of a novel hydroxysuccinimidyl ester derivative of EDOT, 1, and the electrochemical copolymerization of 1 and the bis-EDOT compound, 2 (Scheme 1). 25 It is shown that a redox signal corresponding to the ferrocene units appear upon covalent immobilization of ferrocene-ODN assemblies via amide bond formation, which directly confirm, the probes grafting.…”

A Dual Electrochrome of Poly‐(3,4‐Ethylenedioxythiophene) Doped by N,N′‐Bis(3‐sulfonatopropyl)‐4‐4′‐bipyridinium—Redox Chemistry and Electrochromism in Flexible Devices

“…[7][8][9] Ko et al [10] associated an electrochromic viologen with EDOT; however, the route of derivatizing the monomer and its further polymerization are rather complicated processes. Similarly, post-polymerization functionalization of PEDOT has also been done [11] but there is a paucity of reports wherein electrochromic efficiency of such derivatized polymers has been studied.…”

Potentiometric Ion Sensors Based on Conducting Polymers

“…A large amount of research work has also been devoted to covalent binding of recognition sites, like crown ethers [87 ± 98], benzo-crown ether [99], cyclam (tetraazamacrocycle) [100,101], glucose oxidase [102], cyclodextrin [103], aza crown ethers [104,105], calixarenes [106 ± 108], ferrocene crown ether [109], porphyrin [110], oligo(oxyethylene) [111,112], nucleobases [113], oligonucleotides [114], and antibodies [115] to conducting polymers like polypyrrole and polythiophene [116]. However, conducting polymers with covalently bound ion-recognition sites seems to be a rather unexplored research area in terms of potentiometric ion sensors.…”