Precision Graphene Nanoribbon Heterojunctions by Chain-Growth Polymerization

Area of Science:

• Materials Science
• Nanotechnology
• Organic Chemistry

Background:

• Graphene nanoribbons (GNRs) are key for next-generation nanoelectronics.
• GNR heterojunctions exhibit unique topological electronic phases.
• Precise synthesis of GNR heterojunctions is challenging.

Purpose of the Study:

• To develop a novel strategy for the precision synthesis of GNR heterojunctions.
• To construct GNR heterojunctions with specific armchair and chevron segments (9-AGNR/cGNR).
• To demonstrate the formation of these heterojunctions both in solution and on surfaces.

Main Methods:

• Chain-growth polymerization using Suzuki-Miyaura catalyst-transfer polymerization (SCTP).
• Synthesis of block copolymers (poly-M1/M2) from specific boronic ester monomers.
• Scholl reaction for cyclodehydrogenation and characterization via NMR, SEC, FT-IR, Raman, UV/Vis, and STM.

Main Results:

• Successful synthesis of block copolymers (poly-M1/M2) with controlled molecular weight and narrow dispersity.
• Validation of solution-mediated cyclodehydrogenation to form 9-AGNR/cGNR.
• Demonstration of on-surface formation of pristine 9-AGNR/cGNR using scanning tunneling microscopy.

Conclusions:

• A novel chain-growth polymerization strategy enables precise synthesis of GNR heterojunctions.
• The method allows for controlled formation of 9-AGNR/cGNR in solution and on surfaces.
• This work advances the development of GNR-based nanoelectronic devices.