Tiara[ n]uril: A Glycoluril-Based Macrocyclic Host with Cationic Walls

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Host-Guest Chemistry

Background:

• Development of novel host molecules is crucial for molecular recognition and encapsulation.
• Cationic macrocycles offer unique binding properties for anionic guests.

Purpose of the Study:

• To synthesize and characterize new cationic macrocyclic host molecules based on glycoluril oligomers.
• To investigate the structural modifications for cavity size enhancement.
• To explore the binding potential of these hosts for anionic molecules.

Main Methods:

• Synthesis of novel macrocyclic compounds featuring glycoluril oligomers and pyrazolium moieties.
• Characterization of synthesized derivatives using standard analytical techniques.
• Preliminary pKa studies and guest interaction experiments with L-glutamine.

Main Results:

• Successful synthesis of new cationic macrocyclic host molecules.
• Preparation of several derivatives with varied cavity sizes.
• Initial data suggests potential for binding anionic molecules with H-bond donor groups, exemplified by L-glutamine interaction.

Conclusions:

• The synthesized cationic macrocycles represent a new class of host molecules.
• Structural variations allow for tuning of cavity dimensions.
• These hosts show promise for selective binding of anionic guests, particularly those with hydrogen-bonding functionalities.