Thio-Tetracosulene: A Highly Twisted Molecular Plectoneme

Area of Science:

• Organic Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Chiral macrocycles are crucial in molecular recognition and catalysis.
• Existing chiral macrocycles often rely on specific connection patterns for their topology.
• The synthesis of highly strained and twisted macrocyclic systems remains a significant challenge.

Purpose of the Study:

• To report the synthesis and characterization of a novel, highly twisted chiral macrocycle, thio-tetracosulene 3.
• To investigate the formation mechanism of its unique plectonemic configuration.
• To explore the chiroptical properties of its resolved enantiomers.

Main Methods:

• Sulfur-fluorine annulative substitution reaction.
• Synthesis from a cyclometaphenylene precursor.
• Single crystal X-ray diffraction for structural confirmation.
• Chiral resolution and chiroptical property analysis.

Main Results:

• Successful synthesis of thio-tetracosulene 3, a macrocyclic aromatic compound with a plectonemic configuration.
• Unambiguous structural determination via X-ray crystallography.
• Demonstration that chirality is induced by ring strain, not topological connections.
• Resolution of enantiomers and preliminary investigation of chiroptical properties.

Conclusions:

• Thio-tetracosulene 3 represents the first macrocyclic aromatic compound with a plectonemic configuration.
• The study highlights a new strategy for inducing macrocyclic chirality through inherent ring strain.
• This work opens avenues for designing novel chiral materials with unique topological features.