N-Doped Conical Molecular Carbon Nanotubes

Synthesis of structurally well-defined single-walled carbon nanotubes remains a grand challenge despite tremendous advances in the preparation of nanostructures and nanomaterials. We report herein a template synthesis strategy to construct finite N-embedded carbon-rich nanotubes. The synthesis features the exhaustive N-arylation of an NH-doped octahydro belt[8]arene template with various functionalized aryl bromides and the Ni(0)-promoted fourfold intramolecular homo-coupling reactions between aryl triflate moieties. The acquired compounds adopt conical tubular molecular structures. The small end of the tube has a pure zigzag edge, whereas the large end possesses an alternating zigzag and armchair atomic configuration. The tubular molecules exhibit intriguing photophysical properties owing to their curved π-conjugation systems. The unique cavity endows the nanotube with fullerene recognition ability, forming a C₆₀-host complex structure that resembles the shape of the FIFA World Cup Trophy. This study opens a new avenue to the precise synthesis of nanosized functional molecules of diverse topologies.