Synthesis, electropolymerization, and optoelectronic properties of carbazole containing imidazolium based ionic liquid

Abstract

Herein, we report a prominent initial step toward the rational design of a carbazole-based ionic liquid. Firstly, the novel ionic liquid-based monomer of 1,3-bis[6-(9 H-carbazol-9-yl)-1H-imidazol-3-ium bromide] (coded as M4) salt has been synthesized 9{[6-(1 H-imidazol-1-yl) hexyl]-9 H-carbazole} which was prepared by the addition reaction of imidazole and N-(6-bromohexyl)carbazole, proceeded by connecting N-(6-bromohexyl) carbazole as precursor compound. The structural properties of the M4 have been determined by 1H NMR, 13C NMR, FT-IR, and MS spectral data. The corresponding polymer film (P4) has been synthesized electrochemically on the ITO electrode. The redox behaviors of the resulting polymer have been investigated in detail via cyclic voltammetry and spectroelectrochemistry techniques. The conducting polymer film has exhibited a multi-electrochromic behavior with color changes from transparent, to greenish-yellow and then to blue-green. Moreover, the polymer film has exhibited satisfactory optical contrast, high coloration efficiency, and fast switching time, which made them potential candidates in high-tech applications. © 2023 Elsevier B.V.