Organobase triggered controlled supramolecular ring opening polymerization and 2D assembly

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Naphthalene-diimide (NDI) derivatives are known to self-assemble.
• Controlling the morphology and assembly pathway of NDI derivatives remains a challenge.
• Kinetically controlled aggregation often leads to irregular structures.

Purpose of the Study:

• To investigate a novel method for controlled supramolecular polymerization of NDI derivatives.
• To achieve thermodynamically controlled assembly into specific nanostructures.
• To explore the use of organic bases in directing NDI self-assembly.

Main Methods:

• Synthesis of a carboxylic acid appended NDI derivative.
• Fine-tuning sample preparation to control intramolecular hydrogen bonding.
• Utilizing catalytic amounts of organic bases (DBU, DMAP) to initiate polymerization.
• Characterization of the resulting nanostructures.

Main Results:

• Spontaneous aggregation yielded irregular fibrils.
• Intramolecular H-bonding was used to create a meta-stable monomer.
• Organic bases triggered supramolecular ring-opening polymerization (SROP) via a chain-growth mechanism.
• Ultra-thin 2D nano-sheets were generated through simultaneous H-bonding and π-stacking.
• The 2D polymer acted as a macro-initiator for further SROP cycles, producing extended nano-sheets.

Conclusions:

• A novel, base-catalyzed SROP pathway was established for NDI derivatives.
• This method allows for the controlled formation of ultra-thin 2D nano-sheets.
• The resulting polymers can serve as macro-initiators for scalable nano-sheet production.