Cyclic Voltammetric, Chronocoulometric, and Spectroelectrochemical Studies of Electropolymerized Films Based on (3,4-Ethylenedioxythiophene)-Substituted 3,6-Dithiophen-2-yl-2,5-dihydropyrrole[3,4-c]pyrrole-1,4-dione

Abstract

A new compound with the core luminescent dye unit diketopyrrolopyrrole (DPP), namely 3,6-dithiophen-2-yl-2,5-dihydropyrrole [3,4-c]pyrrole-1,4-dione (DTDPP), attached to 3,4-ethylenedioxythiophene (EDOT) was synthesized. From this monomer, polymer films were prepared on glassy carbon and indium tin oxide surfaces using cyclic voltammetry. The films were characterized using cyclic voltammetry, chronocoulometry, and atomic force microscopy. The electropolymerization of the monomer exhibits reversible electrochemistry that transitions to quasireversible electrochemistry. During electropolymerization, the overpotential for the reduction process exceeds the overpotential for the oxidation process and cyclic voltammetric characterization of the films demonstrates that oxidation is more favored than reduction. Spectroelectrochemical measurements confirm that the polymer films demonstrate electrochromic behavior that correlates to the electrochemical observations during characterization of the films.

Electrochromic Behavior of Donor-Acceptor Polymers Containing Diketopyrrolopyrrole Unit

“…The excellent reversibility was previously reported for the anodic electrochromism of the DPP-thiophene copolymers [13][14][15][16][17][18]. Unfortunately, the DPPbased polymers with the fluorene or triphenylamine donors in this study did not show such a reversible electrochromism in the anodic direction.…”

“…On the other hand, as compared to the semiconducting applications, the electrochromic properties of the DPP-based polymers have rarely been investigated. Most of the reported electrochromic DPP-based polymers were the copolymers with thiophenebased comonomers, and accordingly, they showed only an anodic electrochromism [13][14][15][16][17][18].…”

Evaluating the Practical Use of Digital Video to Study the Effect of Sheet Resistance of Transparent Indium-Tin Oxide Electrodes Using the Galvanostatic Deposition of Poly(o-toluidine)

“…13 Assuming that CPs are homogeneously deposited on the electrode surface, [14][15][16] spectroelectrochemistry, the combination of electrochemical and spectroscopic techniques, analyzes the electrochromic changes of CPs in a limited region by the light beam cross-section (few mm 2 ), and after, the results are extrapolated to the complete surface. 17,18 This technique has provided interesting information about CPs as electrochromic efficiencies, 19 revealing specific electrochromic process [20][21][22][23] or important structural changes [24][25][26] under the electrochemical response or characterizing the CP synthesis 27 in electrodes with relative small surfaces (about 1 cm 2 ). For practical uses, some difficulties can be found for large surface electrodes since the electric field through the electrode substrate shows inhomogeneity, especially in electrodes with an important sheet resistance [28][29][30][31] resulting in defects of the electrochromic response.…”