Chemists construct short nanotube with 40 aromatic rings

Using chemical reactions to knit 40 aromatic rings together, researchers created a short carbon nanotube that’s full of periodic vacancy defects—also known as holes—creating a carbon cylinder reminiscent of fishnet stockings. A team led by the University of Tokyo’s Hiroyuki Isobe built the nanostructure via a nine-step synthesis starting from 1,3-dibromobenzene. The chemists first created a ring of six aromatic groups. They then fashioned four of those rings into a macrocyclic belt. Finally, they added more aromatic rings to produce a cylindrical structure (Science 2019, DOI: 10.1126/science.aau5441). To demonstrate the nanotubes’ ability to enclose other nanostructures, Isobe’s team grew crystals of the cylinders with C₇₀, and the fullerenes fit neatly inside the nanotubes. Computational studies suggest that elongated versions of these holey nanotubes could behave as semiconductors or possess other novel electronic properties. Isobe says the next step is to develop synthetic procedures for making longer tubes of this type.