Pathway Control of π-Conjugated Supramolecular Polymers by Incorporating Donor-Acceptor Functionality

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Nanotechnology

Background:

• Controlling nanoscale orientation of π-conjugated systems is complex due to multiple energy landscapes in supramolecular assembly.
• Existing methods face challenges in precisely directing the aggregation pathways of these materials.

Purpose of the Study:

• To develop a strategy for programming the assembly pathways of π-conjugated supramolecular polymers.
• To investigate the role of donor-acceptor functionalities in controlling supramolecular polymer formation and transformation.
• To understand external seed-induced kinetic-to-thermodynamic transformations.

Main Methods:

• Synthesized monomers incorporating electron-rich donor units (methoxy- or methanthiol-benzene) and electron-poor acceptor units (cyano-vinylenes).
• Studied supramolecular polymerization and assembly processes.
• Investigated external seed-induced transformations and analyzed packing structures (homomeric and heteromeric).

Main Results:

• Achieved programming of π-conjugated supramolecular polymer pathways.
• Formation of parallel-stacked polymers (metastable) via homomeric packing, converting to slip-stacked polymers (stable) via heteromeric packing.
• Demonstrated that donor-acceptor functionality on seed structures accelerates pathway conversion by eliminating the lag phase.

Conclusions:

• The developed strategy effectively controls the aggregation pathways of π-conjugated nanostructures.
• Donor-acceptor interactions are crucial for directing the kinetic-to-thermodynamic transformation in supramolecular polymerization.
• Findings provide valuable insights for designing molecular structures for controlled nanomaterial assembly.