Helical nanographene is probably the smallest spring ever witnessed. For the first time, scientists Kyoto University and Osaka University have described the successful production of hexa-peri-hexabenzohelicene, or “helical nanographene,” in the Journal of the American Chemical Society.
Since these graphene constructs were only theoretically possible earlier, their successful production would enable promising applications such as nanoscale induction coils and molecular springs for use in nanomechanics.
Being a hexagonal lattice formed of a single layer of carbon atoms with exceptional heat and charge transport characteristics, graphene has attracted large-scale research and development interest.
The successful production of helically twisted graphenes, which have a spiral shape, could find major applications; however, its model compounds have not been reported earlier. Although earlier studies have almost attained success, the resultant compounds have never had the anticipated characteristics.
We processed some basic chemical compounds through step-by-step reactions, such as McMurry coupling, followed by stepwise photocyclodehydrogenation and aromatization. We then found that we had synthesized the foundational backbone of helical graphene.
Yusuke Nakakuki, First Author
The helicoid form of the structure was confirmed by the researchers using X-ray crystallography. They also found clockwise as well as counter-clockwise nanographenes. Further investigations revealed that the electronic structure and photoabsorption characteristics of this compound considerably varied from the earlier ones.
This helical nanographene is the first of its kind. We will try to expand their surface area and make the helices longer. I expect to find many new physical properties as well.
Kenji Matsuda, Lead Author