High‐performance hybrid polymer based on bis(alkoxy) ortho‐substituted para‐phenylene

Abstract

AbstractCompared to bis(alkoxy) group para‐substituted para‐phenylene (p‐phenylene) widely used as spacer, the isomer ortho‐substituted p‐phenylene is rarely studied in constructing organic optoelectronic materials. In this manuscript, bis(hexyloxy) group ortho‐substituted p‐phenylene was used to construct hybrid thienylene‐phenylene polymer poly(EDOT‐o‐BE). The density functional theory study indicated the dihedral angles between thienylene and phenylene are 15° for ortho‐substituted EDOT‐o‐BE and 10° for para‐substituted EDOT‐p‐BE. Poly(EDOT‐o‐BE) exhibits the little potential difference between cathodic (0.61 V) and anodic (0.65 V) peaks even at the high potential scan rate, different from bis(alkoxy) para‐substituted control polymer poly(EDOT‐p‐BE). Moreover, the free‐standing poly(EDOT‐o‐BE) film displays better stability than poly(EDOT‐p‐BE) due to the little degradation of molecular chains. Compared to poly(EDOT‐p‐BE), poly(EDOT‐o‐BE) possesses higher ionic transport and different molecular aggregation. These results indicate the positions of side chains have important influence on the properties of conjugated polymer, including molecular configuration, aggregation state, film quality, electrochemical behavior and optical absorption.