Design of triphenylamine appended anthracene derivatives: electro-polymerization and their electro-chromic behaviour

Abstract

Three derivatives (2-TPACNANT, 2,6-TPACNANT and 2,6-TPAANT) of anthracene as a core interior with terminal one or two triphenylamine sides have been designed and synthesized with the aim of obtaining terminal active sites for the purpose of electrochemical polymerization. Electro-deposited polymer films of p-2,6-TPACNANT and p-2,6-TPAANT on ITO/glass electrodes have been obtained within the voltage range from 0 to 1.6 V by repeating cyclic voltammetry (CV) scanning of constant monomer solutions in an electrolyte. The film thickness is easily tuned by controlling the number of the CV scans. Interestingly, these electrogenerated polymer films reveal the reversible electrochemical responses and distinguishable colour changes upon electro-oxidation, which is switched many times by potential modulation. Spectroelectrochemical studies of the electrochromic films on ITO have indicated two colour electrochromism of p-2,6-TPAANT (brick red-dark blue) and p-2,6-TPACNANT (orange-dark blue) with a high colour contrast ratio (ΔT) 87% at 770 nm for p-2,6-TPAANT and 86% at 800 nm for p-2,6-TPACNANT, respectively. These polymer films have the faster response time (1.2–1.3 s) and high colouration efficiency (200–222 cm² C⁻¹). A hand made and simple module has been fabricated in a solidified device composed of the electrodeposited polymers, a pair of ITO electrodes, and a polymer-supported electrolyte to show the potential of using these novel anthracene derivatives as electrochromic materials.