Expanded porphyrin-like structures based on twinned triphenylenes

Area of Science:

• Organic Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Triphenylene derivatives are known for their unique structural and electronic properties.
• Expanded porphyrins are macrocyclic compounds with potential applications in various fields.
• Achieving coplanarity in π-conjugated systems is crucial for tuning electronic and optical properties.

Purpose of the Study:

• To synthesize and characterize novel macrocyclic structures based on triphenylene twins.
• To investigate the impact of bridging dipyrromethene units on the π system's properties.
• To explore the stability and electronic characteristics of these expanded porphyrin derivatives.

Main Methods:

• Synthesis of triphenylene-based precursors.
• Macrocyclization reactions using dipyrromethene linkers.
• Spectroscopic analysis (UV-Vis, NMR) to confirm structure and properties.
• Computational studies to understand electronic structure and stability.

Main Results:

• Successful synthesis of triphenylene-dimer macrocycles bridged by dipyrromethene units.
• The macrocyclic structure enforces coplanarity within the formally antiaromatic π system.
• Significant stabilization of the dipyrromethene chromophores was observed upon macrocyclization.
• These structures can be considered rigid, expanded porphyrin analogues.

Conclusions:

• Triphenylene-dipyrromethene macrocycles represent a new class of rigid, expanded porphyrin derivatives.
• Macrocyclization unexpectedly enhances the stability of the dipyrromethene units.
• The enforced coplanarity in these systems offers opportunities for tuning electronic and photophysical properties.