Carbon Nanotubes (CNTs) have triggered tremendous research efforts due to their many possible applications. Since their properties are very sensitive to size and structure, controlled synthesis of the materials is of importance.

Klaus Müllen and colleagues, Max Planck Institute for Polymer Research, Mainz, Germany, and colleagues, have synthesized cycloparaphenylene (CPP) precursors for the controlled synthesis of ultrashort CNTs (carbon nanobelts). Their structure is based on congested hexaphenylbenzene (HPB) units. The team used Suzuki coupling reactions to synthesize two bent building blocks with a HPB backbone, a dibromide and diboronate. The macrocyclization of these two curved molecules to form a ring proceeded via a third Suzuki coupling.

The oxidative cyclodehydrogenation of the product would lead the formation of ultrashort carbon nanotubes. According to the researchers, this strategy could pave the way for new approaches to a bottom-up synthesis of CNTs.

• π-extended [12]cycloparaphenylenes: from a hexaphenylbenzene cyclohexamer to its unexpected C₂-symmetric congener,
  Florian E. Golling, Silvio Osella, Martin Quernheim, Manfred Wagner, David Beljonne, Klaus Müllen,
  Chem. Sci. 2015.
  DOI: 10.1039/C5SC02547H

Also of Interest

• Chemistry in a Materials World,
  Jonathan Faiz,
  ChemViews Mag. 2015.
  Chemists need to play an active part in the synthesis of materials