Design, Synthesis, Opto–Electrochemical and Theoretical Investigation of Novel Indolo[2, 3‐ <i>b</i> ]naphtho[2, 3‐ <i>f</i> ]quinoxaline Derivatives for <i>n</i> –Type Materials in Organic Electronics

Abstract

Abstract A series of seven new donor–acceptor compounds based on indolo[2, 3‐ b ]naphtho[2, 3– f ] quinoxaline were synthesized by using Buchwald–Hartwig amination reaction between 12–bromo–9–heptyl–5 H –indolo[2, 3– b ]naphtho[2, 3– f ]quinoxaline‐5,15‐(9 H )–dione ( 1 ) and diaryl/cyclic amine ( 2 – 5 ) and by Suzuki–Miyaura coupling reaction of 1 with aryl boronic acid ( 6 – 8 ). The synthesized molecules were studied to determine their absorption, emission, electrochemical, thermal properties. Theoretical properties were also studied by time dependent density functional theory (TD‐DFT). The HOMO and LUMO energy levels of 2–8 are in the range of −6.51 to −6.84 eV and –3.00 to –3.30 eV respectively. Low−lying LUMO energy levels of 2–8 are very similar to well−known n −type materials. On the basis of experimental and theoretical studies synthesized compounds could act as n −type materials in organic electronics.