Molecular engineering of π-extended pyrrolo[1,2-α]quinoxaline-based D–A materials for electrochromic devices

Abstract

Pyrrolo[1,2-α]quinoxaline, a new class of nitrogen-containing skeleton, offers a wide range of applications in the development of optoelectronic materials. In this study, a class of electroactive materials, namely CH₃-PQ-TPA, PQ-TPA, and CF₃-PQ-TPA, was constructed through a molecular engineering strategy by combining triphenylamine with pyrrolo[1,2-α]quinoxaline units bearing different types of substituents calculations and experimental investigations have shown that enhancing the electron-withdrawing ability of substituents decreases the energy gap of the compounds. As a result, CF₃-PQ-TPA exhibits better electrochemical activity. These materials were used to develop electrochromic devices, in which CF₃-PQ-TPA-based devices showed excellent stability and reversibility. This study will provide new strategies for molecular design and molecular skeletons for electrochromic materials.