Synthesis, electrochemical polymerization, and dft calculations of a novel carbazole-edot-based monomer

This thesis focuses on the synthesis, spectroscopic and electrochemical characterization, and electrochemical polymerization of a novel monomer based on carbazole and 3,4-ethylenedioxythiophene (EDOT), specifically 5,7-bis(9-hexyl-9H-carbazol-3-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxine (d1). In addition, theoretical calculations were performed for both the monomer and the synthesized conductive polymers. In the synthesis phase, the d1 monomer was successfully synthesized via Suzuki-Miyaura coupling reaction, and its chemical structure was comprehensively characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) analyses. The polymerizations of EDOT, carbazole and d1 and the synthesis of d1-co-EDOT copolymers by adding different concentrations of EDOT were carried out using the electrochemical polymerization method cyclic voltammetry (CV). The redox properties of these polymers were studied and the optimum polymerization conditions were determined. Fundamental electronic parameters such as HOMO, LUMO energies, and band gaps of the obtained conductive polymers were calculated. The surface morphologies of the polymer films were analyzed using scanning electron microscopy (SEM). Theoretical quantum chemical calculations of the monomer and polymer films were carried out using the Density Functional Theory (DFT) method with Gaussian software, and variations in electronic properties based on different chain lengths were studied. In this study, the novel developed monomer was synthesized with a yield of 70% and for the first time in this study, d1-co-EDOT copolymer was successfully obtained electrochemically via copolymerization with EDOT. Band gaps, redox parameters, and quantum chemical parameters obtained from theoretical calculations for monomer, copolymer, and polymer films were analyzed, highlighting the potential applicability of these materials in organic electronic devices.