Novel electrochromic copolymers based on thiophene-anthracene derivatives via electrochemical polymerization in boron trifluoride diethyl etherate

Two monomers named 5-(10-(thiophen-2-yl)anthracen-9-yl)-2,2'-bithiophene (TABT) and 9,10-di([2,2'bithiophen]-5-yl)anthracene (DBTA) were synthesized via Stille coupling reaction. Electrochemical polymerization for preparation of their homopolymers was failed in boron trifluoride diethyl etherate (BFEE) and acetonitrile (ACN) systems. However, the copolymers of these compounds with thiophene (Th) and 3,4-ethylenedioxythiophene (EDOT) were synthesized and coated onto indium tin oxide (ITO) surface via low -potential electrochemical polymerization in BFEE. Structural and morphological characterizations of these prepared copolymers were taken by FT-IR, X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM). Additionally, spectroelectrochemical and electrochromic properties of these copolymers were also investigated, red-shift effect can be observed on the absorption spectra of the neutral copolymers via substituting EDOT for thiophene as the comonomers and the increase of anthracene content in the copolymer backbone. Switching and electrochemical measurements indicate the prepared copolymers present fast switching rate and good stability. (C) 2016 Elsevier B.V. All rights reserved.