Tuning the self-assembly of rectangular amphiphilic cruciforms

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Nonionic amphiphilic molecules self-assemble into ordered structures.
• The 1,2,4,5-tetrakis(phenylethynyl)benzene (TPEB) core offers a rigid platform for designing complex architectures.
• Modulating peripheral substituents is key to controlling self-assembly outcomes.

Purpose of the Study:

• To synthesize and characterize a series of nonionic amphiphilic cruciforms based on the TPEB skeleton.
• To investigate how modifications in peripheral substituents influence the self-assembly behavior and resulting supramolecular morphologies.
• To understand the driving forces behind the observed self-assembly processes through experimental and theoretical approaches.

Main Methods:

• Synthesis of TPEB-based nonionic amphiphiles with varying peripheral chains.
• Characterization of self-assembled structures using techniques like microscopy (visualized).
• Computational modeling to elucidate the mechanisms of self-assembly, including π-stacking and tail interdigitation.

Main Results:

• Amphiphiles with linear chains formed 2D structures; dendronized chains led to twisted ribbons or hindered assembly.
• Compound 2 exhibited solvent-dependent morphologies, forming 2D structures via π-stacking and tail interdigitation.
• Steric hindrance from dendronized wedges and tail interdigitation directed assembly into helical aggregates (cruciform 3) or amorphous material (TPEB 4).

Conclusions:

• Peripheral substituent design is crucial for controlling the self-assembly of TPEB-based amphiphiles.
• π-stacking and peripheral chain interactions (interdigitation, steric effects) dictate the final supramolecular morphology.
• This study provides valuable insights for designing molecules with predictable self-assembly characteristics.