Donor-pi-bridge-acceptor fluorescent polymers based on thiophene and triphenylamine derivatives as solution processable electrochromic materials

A series of novel donor-pi-bridge-acceptor type conjugated polymers bearing 3,3-bis((2-ethylhexyloxy) methyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine and triphenylamine (TPA) derivatives are synthesized via Stille coupling. The optical, fluorescent, electrochemical, spectroelectrochemical and electrochromic switching properties are characterized. The polymers display excellent solubility in low-boiling point organic solvents. Different electron-withdrawing pendent groups attached on TPA exert great influence on polymer's fluorescent and electrochromic properties. All polymers show large transmittance changes in near-infrared region and reveal fast switching from one second to several seconds. (C) 2015 Published by Elsevier B.V.