Available online at www.sciencedirect.com Electrochimica Acta 53 (2008) 4875–4882 Syntheses of electroactive layers based on functionalized anthracene for electrochromic applications A. Yildirim a , S. Tarkuc a , M. Ak a,b , L. Toppare a,∗ a Department of Chemistry, Middle East Technical University, 06531 Ankara, Turkey b Department of Chemistry, Pamukkale University, 20017 Denizli, Turkey Received 6 December 2007; received in revised form 25 January 2008; accepted 8 February 2008 Available online 15 February 2008 Abstract A new monomer (DTAT) was synthesized via linking 3,4-ethylenedioxythiophene (EDOT) on anthracene. The polymer, P(DTAT) was electrosyn- thesized by anodic oxidation of the corresponding monomer in 0.1 M LiClO 4 acetonitrile (ACN) solution. The optical properties, the absorption spectra and the kinetics, were examined. Spectroelectrochemical analysis showed that P(DTAT) has an electronic band gap (due to –* transition) of 1.57 eV at 776 nm. Copolymers of DTAT with EDOT were prepared in ACN/LiClO 4 (0.1 M) solvent–electrolyte couple by varying applied potential. The incorpo- ration of an EDOT into the full conjugated backbone, DTAT, affects its optical behavior resulting in different colors; a claret red neutral state, gray and red intermediate states and a blue oxidized state. © 2008 Elsevier Ltd. All rights reserved. Keywords: Conducting polymers; Electrochemical copolymerization; Electrochromism; Electrochromic materials; Electrochromic devices 1. Introduction In the last two decades, polymers with a regular alter- nating arrangement of an aromatic -electron system are currently receiving attention for various important technological applications. Research was focused on their conducting, electro- luminescent and photoluminescent properties and their potential application in electronic and electro-optic devices, in particular in light emitting diodes (LED) [1,2]. Enhanced delocalization of -electrons through the -conjugation on the backbone would improve optical and electric properties of the polymers, includ- ing semiconducting properties in the doped state [3]. Also, reactivity of the monomer will affect the properties of the resulting polymer. Due to their availability and relative ease of polymerization, electron-rich heterocycles such as thio- phene (Th) and 3,4-ethylenedioxythiophene (EDOT) are the most common monomers used for electropolymerization [4,5]. Derivatization of the monomer structure prior to polymeriza- tion, synthesis of copolymers, and association of the conducting ∗ Corresponding author. Tel.: +90 3122103251; fax: +90 3122103200. E-mail address: toppare@metu.edu.tr (L. Toppare). polymer (CP) with other materials in order to prepare hybrid materials where the properties of both components are associ- ated with a possible synergic effect [6]. Anthracene polymers having extended -conjugation are also of considerable interest for their photoluminescence and electroluminescent properties [7,8]. It is known that the ortho position substitutions (Th, EDOT) of the phenyl ring modify the degree of conjugation (extended –* bonding system) [9]. Palladium catalyzed cross-coupling reaction of organometal- lic species with arylhalides (the Stille coupling) provides this extension in organic compounds. Development of synthetic methodology makes it possible to design oligomers, which per- mits color and charge injection tunable. Due to the conjugated structures of the corresponding monomers, these polymeric sys- tems presented the advantage of being electrosynthesized at much lower oxidation potentials than that of thiophene [10]. Switching the polymer between two or more redox states gen- erates different visible region electronic absorption bands [11]. In the first part of this study, the electrosynthesis of a con- ducting polymer P(DTAT), obtained from a newly synthesized monomer with anthracene core unit was achieved. The optoelec- trochemical behavior and switching ability of the polymer were investigated. Second part of the study was devoted to investigate 0013-4686/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.electacta.2008.02.026