Chemical engineering around the 5,12-dihydroindolo[3,2-a]carbazole scaffold: Fine tuning of the optical properties of visible light photoinitiators of polymerization

5,12-Dihydroindolo[3,2-a]carbazole is a promising scaffold for the design of visible light photoinitiators polymerization due to simultaneous presence two carbazole moieties that can be differently functionalized. Notably, redshift absorption spectra facilely obtained by nitration one carbazoles, second group being functionalized with various groups. Dinitration 5,12-dihydroindolo[3,2-a]carbazole another efficient approach designing dyes strong absorptions extending over range. In this work, series 36 compounds never reported in literature and differing substitution pattern have been designed synthesized. possibility push–pull Knoevenagel Claisen Schmidt reactions, introduce electroactive groups such as thiophene Suzuki cross-coupling reactions or water soluble chromophore has explored. To evidence interest these structures, photopolymerization experiments carried out at 405 nm acrylates examined thick thin films. support efficiency, mechanisms involved free radical established combination techniques including UV–visible fluorescence spectroscopy, cyclic voltammetry photolysis experiments.