Tetrathio and tetraseleno[8]circulenes: synthesis, structures, and properties

Area of Science:

• Organic Chemistry
• Materials Science
• Computational Chemistry

Background:

• [8]circulenes are a class of macrocyclic aromatic compounds.
• Octabromotetraphenylene serves as a versatile precursor for synthesizing complex polycyclic systems.

Purpose of the Study:

• To synthesize novel sulfur and selenium-bridged [8]circulenes.
• To investigate the structural, photophysical, electrochemical, and electronic properties of these new compounds.
• To computationally assess the antiaromaticity of the synthesized [8]circulenes.

Main Methods:

• Synthesis of sulfur and selenium-bridged [8]circulenes from octabromotetraphenylene.
• X-ray crystallographic analysis for unambiguous structure determination.
• Photophysical and electrochemical measurements.
• Nuclear Independent Chemical Shift (NICS) calculations to evaluate antiaromaticity.

Main Results:

• Successful preparation of novel sulfur and selenium-bridged [8]circulenes.
• X-ray crystallography confirmed the molecular structures.
• Photophysical and electrochemical data indicate potential for electronic material applications.
• Computational studies demonstrated a highly antiaromatic character in the central eight-membered ring of tetrathio[8]circulene and tetraselenium[8]circulene.

Conclusions:

• The synthesized sulfur and selenium-bridged [8]circulenes are structurally characterized and possess unique electronic properties.
• These compounds show promise for applications in organic electronics.
• The central ring in these specific [8]circulenes exhibits significant antiaromaticity, offering insights into their electronic behavior.