Kinetic Traps to Activate Stereomutation in Supramolecular Polymers

Area of Science:

• Supramolecular Chemistry
• Organic Materials Science
• Stereochemistry

Background:

• Carbonyl-bridged triarylamines (CBTs) are known for their self-assembly properties.
• Helical structures in organic materials are crucial for various applications, including chiral recognition and optoelectronics.
• Understanding the factors controlling stereomutation in coassembly is essential for designing functional chiral materials.

Purpose of the Study:

• To investigate the helical stereomutation in kinetically controlled coassembly of CBTs.
• To explore the influence of chiral "sergeants" and achiral "soldiers" on the resulting helical structures.
• To elucidate the mechanisms of chirality transfer and J-aggregate formation in these systems.

Main Methods:

• Sergeants-and-soldiers (SaS) coassembly experiments using chiral CBTs ((S)-1 or (R)-1) and achiral CBT 2.
• Kinetic control of coassembly through varying cooling rates.
• Analysis of helical structure and J-aggregate formation.

Main Results:

• Coassembly of chiral and achiral CBTs results in tunable helicity.
• Helicity is dependent on the percentage of the chiral sergeant and the cooling rate.
• J-aggregates with inverse handedness are formed, influenced by the stability of kinetic traps and inherent chiral species.

Conclusions:

• Kinetically controlled coassembly of CBTs offers a method for tunable helical structures.
• Chirality transfer is effectively modulated by experimental conditions, leading to predictable J-aggregate handedness.
• This study provides insights into the design of advanced chiral organic materials with controlled supramolecular organization.