Double-Cyclized Dipeptides for Hierarchical Self-Assembly Into Crystalline Macroscopic Superhelices

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Chirality Studies

Background:

• Cyclic peptides are valuable for their stable structures and biological activities.
• They serve as essential components in developing functional chiral materials.
• Persistent structures of cyclic peptides are key to creating advanced materials.

Purpose of the Study:

• To synthesize and characterize a novel double-cyclized dipeptide macrocycle.
• To explore its self-assembly into hierarchical superhelical structures.
• To demonstrate multiscale chirality transfer and applications in chiroptical materials.

Main Methods:

• Synthesis of a macrocyclic arene embedded with a cyclodipeptide via further cyclization of modified cyclic diphenylalanine.
• Bottom-up self-assembly in solution to form hierarchical helical structures.
• Controlled assembly by adjusting kinetic conditions (temperature, concentration, solvent, enantiomeric ratio).

Main Results:

• Successful synthesis of a unique, rigid double-cyclized dipeptide macrocycle.
• Formation of macroscopic superhelical structures at centimeter scale through self-assembly.
• Demonstration of precise control over assembly patterns, yielding both rigid and flexible arrangements.
• Encapsulation of cationic dyes within superhelices, enabling ground-state and excited-state chirality transfer.

Conclusions:

• The double-cyclized dipeptide serves as a versatile building block for hierarchical self-assembly.
• This work establishes a bottom-up approach for multiscale chirality transfer from molecular to macroscopic levels.
• The developed superhelical structures offer a promising template for designing novel macroscopic chiroptical materials.