A new approach to the Schiff base-substituted oligophenols: The electrochromic application of 2-[3-thienylmethylene]aminophenol based co-polythiophenes

Two new copolymers were synthesized by electrochemical polymerization of 2-[3-thienylmethylene]aminophenol (2,3-TMAP) and poly-2-[3-thienylmethylene]aminophenol (P-2,3-TMAP) with thiophene (Th) and the obtained thiophene copolymers were examined as electrochromic materials. Electro copolymerization reactions of the compounds were performed in acetonitrile (AN)/boron trifluoride ethyl etherate (BF3EtE) solvent mixture (9:1, v/v) where LiClO4 utilized as the supporting electrolyte. After electro copolymerization reaction, obtained electrochromic films deposited on ITO glass plates, 2,3-TMAP-co-Th and P-2,3-TMAP-co-Th, were investigated as spectroelectrochemically. The new electrochromic materials derived from Schiff base substituted-phenol/oligophenols are red colored at low potentials and blue colored at high potentials. Electro copolymerization mechanism was identified. Spectroelectrochemical monitoring showed good absorption recovery for P-2,3-TMAP-co-Th, while absorbance decrease was observed for 2,3-TMAP-co-Th during the repeated potential scans. Suitable potential range for operating the device from red to blue was found to be between 0 and +1.4 V. P-2,3-TMAP-co-Th showed 12–13% transmittance changes at applied potentials and the response times were 3.1 and 4.1 s for 476 and 800 nm, respectively. As a result P-2,3-TMAP-co-Th may be good candidate for electrochromic devices and can be thought as a feasible nominee for anodically coloring electrochromic layers in ECDs.

New kind of Schiff base substituted oligophenol, poly-2-[3-thienylmethylene]aminophenol (P-2,3-TMAP), and its monomer compound (2,3-TMAP) were investigated as the electrochromic behaviours. These imine coupled thiophene compounds were electopolymerized on ITO glass plate in the presence of thiophene as the comonomer agents. The obtained electrochromic copolymers were red colored at low potentials and blue colored at high potentials. Spectroelectrochemical monitoring showed good absorption recovery for P-2,3-TMAP-co-Th, while absorbance decrease was observed for 2,3-TMAP-co-Th during the repeated potential scans. P-2,3-TMAP-co-Th showed 12-13% transmittance changes at applied potentials and the response times were 3.1 and 4.1s for 476 and 800 nm, respectively. As a result P-2,3-TMAP-co-Th may be good candidate for electrochromic devices and can be thought as a feasible nominee for anodically coloring electrochromic layers in ECDs.Figure optionsDownload as PowerPoint slideResearch highlights
► Iminophenol coupled polythiophene was developed as red-blue electrochromic device.
► The polymer showed good absorption recovery in the range of 0-1.4 V.
► Transmittance changes were 12–13% at applied potentials.
► Response times were 3.1 and 4.1s for 476 and 800 nm, respectively.
► New polymer can be used for anodically coloring electrochromic layers in ECDs.