Dyes and Pigments, vol.223, 2024 (SCI-Expanded)
Poly(3,4‐ethylenedioxythiophene) (PEDOT) is the most popular conducting polymer in the field of optoelectronics. In this study, the electrochemical and spectral properties of the silicon(IV) phthalocyanine (SiPc) and of a PEDOT were combined, and the electrochromic property was imparted to SiPc by modification of the axial positions of the Si4+ cation of SiPc with 3,4‐ethylenedioxythiophene (EDOT) groups. For this purpose, SiPc-EDOT was synthesized and characterized as to its electrochemistry and spectroelectrochemistry in nonaqueous media. Three reversible reduction couples at −0.51, −0.92, and −1.62 V and two oxidation processes at 1.16 and 1.73 V were observed for SiPc-EDOT in dichloromethane (DCM) containing tetrabutylammonium perchlorate (TBAP). In situ spectroelectrochemical analysis showed that the reductions and the first oxidation process of SiPc-EDOT were Pc-centered and the second oxidation process was EDOT-centered. The EDOT-based redox process at 1.73 V triggered the coating of SiPc-EDOT on the electrode surface as the SiPc-PEDOT film due to the electrooligomerization of the oxidative cationic form of EDOT groups during the repetitive voltammetric cycles. The electropolymerized SiPc-PEDOT film on the different electrode surfaces (ITO, GCE, ITO/Nf) yielded a conjugated polymer, which was characterized by cyclic voltammetry, UV–vis spectroelectrochemistry, Raman and FT-IR spectroscopies. The EDOT modification of SiPc supplied boost electrochromic performance in large percent transmittance change (Δ%T = 50 %), high coloration efficiency (η = 530 cm2 C−1), fast response times, and high cycle stability.