Naphthalimide clicked polycarbazoles: Synthesis, characterization, and investigation of their optical, electrochemical and spectroelectrochemical properties

Abstract

In this study, naphthalimide has been clicked with the N9-and C2-positions of carbazole, and two new monomers named KN and KC were synthesized, respectively. The fluorescent group naphthalimide and polymerizable group carbazole have been synthesized with Huisgen's 1,3-dipolar cycloaddition reaction in water environment by taking advantage of the linker ability of click chemistry to react easily and quickly. Monomers have been characterized via H-1 NMR and FT-IR spectroscopy and electropolymerized in acetonitrile/boron trifluoride diethyl etherate (BFEE) by cyclic voltammetry technique. The electrochemically synthesized PKC has superior electrochemical and optical properties compared with PKN. Herein, the electron-rich nitrogen of the C2-substituted carbazole in PKC makes carbazole oxidation easier than the N9-substituted carbazole in PKN. Be-sides, another structural difference is the presence of the oxygen group in KC. This difference between the two structures is due to oxygen and nitrogen atom donating to the carbazole aromatic pi system which increases the electron density in the carbazole.