Synthesis, characterization and DFT study of new anthracene-based semiconducting polyethers for OLED application

Abstract

New soluble semiconducting anthracene-based polyethers (An-BPS and An-TDP) were synthetized via the Williamson polycondensation of 9,10-dichloromethylanthracene with 4,4′-thiodiphenol (TDP) and bisphenol S (BPS), respectively. The polymers were investigated by density functional theory (DFT): the structural and optoelectronic properties, frontier molecular orbitals (HOMO/LUMO), as well as the infrared, absorption and fluorescence spectra were discussed. The polyethers structures were confirmed by NMR and FTIR spectroscopies, revealing good agreements between experimental and theoretical results. Quasi-identical absorption and blue emission properties were obtained for both polymers in dilute solutions, with a higher fluorescence efficiency for An-BPS. The cyclic voltammetry analysis of these electrochemically active materials showed a higher electron affinity for An-BPS and a lower ionization potential for An-TDP. The DFT calculations showed that the HOMO/LUMO frontier energy distributions are confined on the anthracene moiety in An-BPS. However in An-TDP, the LUMO distribution is localized on anthracene group, while the HOMO is on the TDP unit. The electric behavior of organic light-emitting diodes (OLEDs) based on these macromolecular structures has been investigated via numerical simulation using Silvaco TECAD software. Good electrical properties are estimated, with a low turn on voltages of 3.1 V and 2.9 V for An-TDP and An-BPS, respectively. However, An-BPS showed improved current conductivity, which makes it a good candidate for OLEDs.