General Strategy to Synthesize Star-Shaped Nanographenes with Controllable Symmetries

Area of Science:

• Materials Science
• Organic Chemistry
• Nanotechnology

Background:

• Nanographenes are carbon-based nanomaterials with diverse structures.
• These materials show promise for applications in photonics, optoelectronics, and spintronics.
• Controlling nanographene topology is crucial for tuning their properties.

Purpose of the Study:

• To develop a controllable synthesis strategy for star-shaped nanographenes.
• To investigate the relationship between molecular symmetry and electronic/optical properties.
• To expand the range of accessible nanographene structures with tailored functionalities.

Main Methods:

• Utilized a "from-core-to-branch" synthetic approach.
• Synthesized star-shaped nanographenes with varying symmetries.
• Characterized the electronic and photoluminescent properties of the synthesized materials.

Main Results:

• Successfully synthesized star-shaped nanographenes with controlled topologies.
• Observed a direct correlation between molecular symmetry and the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap.
• Demonstrated symmetry-dependent photoluminescence quantum yields (PLQYs).

Conclusions:

• Precise control over molecular topology is essential for tuning nanographene properties.
• The developed synthetic strategy enables the creation of novel star-shaped nanographenes.
• This work provides a pathway for designing nanographenes with specific optoelectronic and spintronic characteristics.