Nanographene with Multiple Embedded Heptagons: Cascade Radical Photocyclization.

Area of Science:

• Materials Science
• Organic Chemistry
• Nanotechnology

Background:

• Heptagons are common in graphenic materials, but synthesizing nanocarbons with multiple heptagons is difficult.
• Precise control over the assembly of complex carbon nanostructures remains a synthetic challenge.

Purpose of the Study:

• To develop a method for synthesizing multi-heptagon-embedded nanocarbons.
• To investigate the structural, electronic, and optical properties of novel multi-heptagon nanocarbons.

Main Methods:

• Photo-induced radical cyclization (PIRC) was employed for the synthesis.
• A six-fold cascade PIRC reaction was utilized to construct a complex nanographene.
• Structural validation was performed using experimental and theoretical methods.
• Electrochemical studies were conducted to analyze electronic properties.

Main Results:

• A novel nanographene containing six heptagons was successfully synthesized.
• The nanographene exhibited a unique Monkey-saddle-shaped conformation.
• Experimental and theoretical analyses revealed non-aromatic heptagons and aromatic peripheral rings.
• The nanographene displayed a similar optical gap to planar analogues due to structural effects.
• Nitrogen-doping led to low-lying oxidation potentials.

Conclusions:

• Photo-induced radical cyclization is an effective strategy for synthesizing complex multi-heptagon nanocarbons.
• The synthesized nanographene possesses unique structural and electronic characteristics.
• The study provides insights into the structure-property relationships of non-planar nanographenes.