Study On Synthesis And Characterization Of Several New Dithienylpyrroles Derivatives, And Electro-and Spectro-chemical Properties And Electrochromic Behaviors Of Their Polymer Films

Electrochromism is defined as the phenomenon that optical properties (reflectance, transmittance, absorption, etc.) of the materials undergo stable and reversible change when the potential is applied. The reversible change of the performances of the transmission and colors of the materials can be found in appearance. The materials are named as electrochromic materials and the devices based on these materials are called electrochromic devices (ECD).Electrochromic materials include two sorts:inorganic electrochromic materials and organic electrochromic materials. WO3 is a typical representative of inorganic electrochromic materials. At present, the functional ECD based on WO3 have been successfully industrialized. While organic electrochromic materials are mainly made up of polythiophene,polyaniline,polypyrrole,viologen,thiazine,anthraquinone and metal phthalocyanine compounds. Viologen-based ECD have been successfully applied in some fields, such as anti-glare vehicle mirror. Recently years, in order to gain electrochromic materials of more excellent properties which can overcome the lack of properties in single material, researchers are turning to composite electrochromic materials.In this paper a series of new organic composite electrochromic materials were designed and synthesized. They are dithienylpyrroles bearing anthraquinone units and amino units and double dithienylpyrroles. The structures of these compounds were characterized and ensured by]H NMR, 13C NMR, MS and FT-IR. The corresponding polymer films were successfully synthesized via electropolymerization in three-electrode system. Their spectroelectrochemical properties, electrochromic behavior, thermal stability, surface morphology and fluorescence were investigated by cyclic voltammetry, UV-vis absorption, thermogravimetric analysis, scanning electron microscopy and fluorescence emission spectra. The results show that these polymer films have excellent spectroelectrochemical and electrochromic properties. By comparing with these polymer films, several compounds with excellent electrochromic properties were chosen to assemble a summary of the simple electrochromic devices. The results show that the simple ECD perform multicolors, and they are expected to apply in commercial display technology by further optimization and improvement.