Electropolymerization of thiazole derivative bearing thiophene and its application in capacitors and electrochromic devices

Abstract A thiazole derivative bearing thiophene as a monomer compound was synthesized and electropolymerized at carbon, gold, platinum, and fluorine doped tin oxide electrodes. From an in-depth analysis of cyclic voltammograms at several scan rates, deposited polymer layers, comprising thiophene functional groups, were shown to clearly exhibit capacitive behavior. This property is related to anion intercalation into these layers during charging and was demonstrated in this study using electrochemical quartz crystal microbalance experiments. It was also shown that in the case of both tetrafluoroborate and hexafluorophosphate anions, the molar ratio of monomers to anions was approximately 1:0.6, which is estimated as the ratio of anion intercalation into thiophene moiety of the polymer layers. This confirms that the capacitance properties of these deposited polymer layers have high stability against electrochemical perturbation. Furthermore, spectroelectrochemistry data obtained during this study indicate that these layers also have switchable electrochromic properties in the visible range.