Segregated co-assembly of fullerene–triphenylene hybrid dendrimers in columnar mesophases showing ambipolar charge transport

Abstract

Liquid-crystalline dendrimers with donor triphenylene as the peripheral discotic mesogen and acceptor fullerene as the dendrimer core have been designed and synthesized with the aim of achieving heterojunction ambipolar charge-transport columnar materials. While the low-generation fullerene-core discotic liquid-crystalline dendrimers self-organize into a lamellar structure, the co-assembled mixtures through blending with a low-molar-mass triphenylene derivative successfully form hierarchical columnar superstructures with segregated stacking of the triphenylene discs and fullerene moieties in discrete columns. Such donor–acceptor segregated columnar materials exhibit ambipolar charge-transport behavior, with rather high mobilities reaching 0.012 cm² V⁻¹ s⁻¹ for holes and 0.005 cm² V⁻¹ s⁻¹ for electrons, as measured by the time-of-flight (TOF) technique. The present work provides a simple and versatile approach for the design of ambipolar conductive columnar liquid-crystalline hybrid dendrimer materials that are promising for organic electronic applications.