Helical Aggregates of Building Blocks Formed In Situ from Five Components

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Materials Science

Background:

• Achiral cationic perylene-3,4-dicarboximide (1) with a phenylboronic acid group was studied.
• Uridine monophosphate (UMP) contains a cis-diol moiety and an imide group.
• Hg2+ ions are known to coordinate with imide groups.

Purpose of the Study:

• To investigate the induced helical aggregation of an achiral perylene dye.
• To explore the synergistic effects of UMP and Hg2+ on aggregation.
• To demonstrate chirality transfer to supramolecular assemblies.

Main Methods:

• Spectroscopic analysis (UV-Vis, CD) to observe aggregation and chirality.
• In-situ construction of a five-component building block (1-U-Hg2+-U-1).
• Evaluation of binding affinity and selectivity for UMP and Hg2+.

Main Results:

• Helical aggregation of dye 1 occurs only in the presence of both UMP and Hg2+.
• Formation of a specific five-component building block drives the aggregation.
• Strong exciton-coupled circular dichroism signals demonstrate P-helicity transfer.
• Synergistic enhancement of binding affinity and selectivity for UMP and Hg2+ was observed.
• A high g-factor of 1.4×10-2 indicates efficient chirality induction.

Conclusions:

• A strategy for in-situ construction of supramolecular building blocks from multiple components was demonstrated.
• Weak and less selective interactions among components can lead to highly functional aggregates.
• Simplified design of constituent components allows for diverse supramolecular functions.