JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY, vol.50, no.6, pp.588-595, 2013 (SCI-Expanded)
Here we report on the synthesis and characterization of pyrazole based conducting polymers and utilization of these polymers in electrochromic devices. For this purpose, 3,5-di-thiophen-2-yl-1H-pyrazole (DThPz) was synthesized via a Knorr type reaction and it was electrochemically polymerized. The resultant homopolymer had a band gap of 2.6eV and displayed yellow to mode beige coloration upon doping. In order to enhance the switching characteristic; electrochemical copolymerization of DThPz in the presence of 3-hexylthiophene (HTh) and N-methyl pyrrole (NMP) was performed. Spectroelectrochemistry analysis of poly(DThPz-HTh) reflected electronic transitions at 405 and 740nm due to * transition and charge carrier band formation, respectively. The polymer displayed color change from chrome yellow to blue upon doping. Poly(DThPz-NMP), on the other hand had a * transition at 355nm and formation of new transitions at around 750nm was observed. Additionally, as an application, dual-type electrochromic devices based on both poly(DThPz-HTh) and poly(DThPz -NMP) were assembled and characterized via spectroelectrochemistry, kinetic and colorimetry studies.