Structurally Diversified Calix[3]phenoxazines: Synthesis, Solid-State Conformational Investigation, and Host-Guest...

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Materials Science

Background:

• Phenoxazine-based macrocycles are of interest for host-guest chemistry.
• Developing new macrocyclic architectures is crucial for advancing molecular recognition.

Purpose of the Study:

• To report a new class of phenoxazine-based macrocyclic arenes: calix[n]phenoxazines.
• To synthesize and characterize structurally diverse calix[3]phenoxazines.
• To investigate the host-guest properties of these new macrocycles.

Main Methods:

• Synthesis of substituted calix[3]phenoxazines.
• Single crystal X-ray diffraction for structural determination.
• Density Functional Theory (DFT) calculations to probe electronic properties and interactions.

Main Results:

• Successful synthesis of structurally diversified calix[3]phenoxazines with yields ranging from 30% to 70%.
• Single crystal analysis confirmed the macrocyclic structure.
• DFT calculations revealed electron-rich cavities within the calix[3]phenoxazine framework.
• Demonstrated selective encapsulation of electron-deficient guests.

Conclusions:

• Calix[3]phenoxazines represent a novel class of macrocyclic hosts.
• The electron-rich cavities enable selective guest binding through noncovalent interactions.
• These findings open avenues for applications in molecular recognition and sensing.