Design and Synthesis of Conjugated Aromatic Macrocyclic Rings That Can Serve as Carbon Nanotube Segments

Design and synthesis of conjugated aromatic macrocyclic rings that are directly linked by C-C bonds has been currently attracting wide interests because these aromatic macrocyclic rings can be used for synthesis of single-walled carbon nanotubes through the “bottom-up” stratety. Conventional methods of preparing carbon nanotubes, such as arc method, chemical vapor deposition method and so on, are difficult to form the uniform single-walled carbon nanotubes. This “bottom-up” synthetic strategy provides a feasible method for the highly efficient synthesis of highly homogeneous single-walled carbon nanotubes. For this reason, the “bottom-up” synthetic strategy has become an on-going hot spot for the synthesis of single-walled carbon nanotubes, although it is still a big challenge. This article summarizes new progress in the design and synthesis of two-dimensional (2D) carbon nanorings, 2D carbon nanobelts and three-dimensional (3D) carbon nanocages. In particular, this article focuses on the design principle and synthesis methods of 2D carbon nanorings and highlights the polycyclic aromatic hydrocarbon (PAHs) carbon nanorings. Polycyclic aromatic hydrocarbons usually have excellent photoelectric properties. Thus, the conjugated carbon nanohoops constructed by these PAHs moieties may exhibit new photoelectric properties.