Diazadioxa[8]circulenes: planar antiaromatic cyclooctatetraenes

Area of Science:

• Organic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Cyclooctatetraenes are a fundamental class of organic compounds with unique electronic properties.
• Exploring new derivatives of cyclooctatetraenes can lead to novel materials with tailored characteristics.
• Antiaromaticity in cyclic systems presents an interesting area of study in physical organic chemistry.

Purpose of the Study:

• To synthesize and characterize a new class of antiaromatic planar cyclooctatetraenes, termed diazadioxa[8]circulenes.
• To develop a general and efficient synthetic protocol for these novel compounds.
• To investigate and compare the optical and electrochemical properties of diazadioxa[8]circulenes with related structures.

Main Methods:

• Acid-mediated oxidative dimerization of 3,6-dihydroxycarbazoles.
• One-pot synthesis involving the formation of two C-C and two C-O bonds.
• Detailed characterization using optical and electrochemical techniques.
• Computational analysis, including NICS calculations, to assess antiaromaticity.

Main Results:

• Successful synthesis of diazadioxa[8]circulenes in high yields.
• A general, one-pot synthetic protocol was established.
• Comprehensive optical and electrochemical properties were determined.
• NICS calculations confirmed the antiaromatic character of the central cyclooctatetraene ring.

Conclusions:

• A new class of stable, planar, antiaromatic cyclooctatetraenes, diazadioxa[8]circulenes, has been synthesized.
• The developed synthetic method is efficient and broadly applicable.
• The study provides insights into the electronic properties and antiaromatic nature of these novel compounds.