Yoshihiro Miyake

Abstract Tetrathia[8]circulene is a heteroaromatic framework consisting of an eight‐membered ring fused with four thiophene and four benzene units, whose electronic properties are highly tunable by peripheral substituents. Herein, we report the synthesis of a perfluorinated tetrathia[8]circulene bearing hexafluorocyclopentene rings via sequential Suzuki–Miyaura and C─H/C─Cl coupling reactions. Single‐crystal X‐ray diffraction analysis revealed a highly planar π‐conjugated core with dense F···F contacts, leading to a two‐dimensional layered and one‐dimensional columnar packing structure. UV–vis absorption spectroscopy and cyclic voltammetry demonstrated that the electron‐withdrawing hexafluorocyclopentene units substantially lower the LUMO energy level, resulting in a reduced HOMO–LUMO gap and enhanced electron‐accepting character. Density functional theory calculations further supported these findings by correlating the perfluoroalkyl annulation with frontier orbital stabilization and excited‐state properties.

Mimicking the interconvertible carbon allotropes of 2-dimensional (2D) graphene and 1-dimensional (1D) carbon nanotubes (CNTs), herein we report the in situ transformation of 2D π-conjugated covalent organic frameworks (COFs) sheet into 1D nanotubular structures via self-assembly the sheets at solvent interfaces. The facile “roll-sheets” self-assembly resulted in coaxial nanotubes with uniform cross-sectional diameter, which was realized for diazapyrene-based COFs but not for the corresponding pyrene COF, although both possess similar chemical structures. Upon replacing the carbon atoms at 2,7-positions of pyrene with nitrogen, contrasting optical and electronic properties were realized, reflecting the rolled structure of the conjugated 2D sheets. The nanotubes exhibited concerted electronic- and proton-conducting nature with stable conducting pathways at ambient conditions. The nitrogen centers act simultaneously as the site for charge carrier doping and proton acceptors, as evidenced by the high photo- and electrical conductivity, as well as the record proton conductivity (σ = 1.98 S cm ⁻¹ ) results. The present diazapyrene-based 1D nanotubular COF serves as a unique materials platform with electronic conduction in the wall and proton conduction in the core, respectively.