Based on the concept of minimizing the charge transfer complex effect, the diamine monomer which contains amide bond bridged adamantane group and triarylamine unit was synthesized. Subsequently, two colorless polyimides with excellent electrochemical stability and high fluorescence quantum yield were prepared by polycondensation of the aforementioned diamine monomer with 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride and 4,4'-hexafluoroisopropylidene)-diphthalic anhydride, respectively. CPIs coatings ranging from colorless to oxidized blue exhibit excellent electrochromic behaviors and optical transmittance of 80 %, which is 60 % after 15,000 s electrochemical cycles. Interlayer electrochromic displays constructed through a simple strategy can display tailored patterns during electrochemical process. The color contrast between neutral state and oxidized state is strong, which can be used for encrypted transmission of information. Furthermore, the CPI synthesized from HPMDA (PI-HPMDA) demonstrated remarkable electrofluorescence performance, with the fluorescence of the film being controlled by applying voltage. The solution of PI-HPMDA exhibited a fluorescence quantum efficiency of 32.5 %, and the fluorescence intensity of PI-HPMDA could be reduced in the presence of Fe3+. he responsiveness of PI-HPMDA to Fe3+ is expected for specific ion probes.
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