Aromatic fused heterocyclic [22] macrocycles with NIR absorption

Area of Science:

• Organic Chemistry
• Materials Science
• Spectroscopy

Background:

• Porphyrins are vital macrocyclic compounds with diverse applications.
• Achieving near-infrared (NIR) absorption in small π-conjugated systems remains a challenge.
• Heterocyclic modifications offer pathways to tune electronic properties.

Purpose of the Study:

• To synthesize and characterize novel aromatic [22] heteroporphyrins.
• To investigate the potential of these macrocycles for NIR absorption.
• To understand the structural basis for NIR absorption in these systems.

Main Methods:

• Organic synthesis of three related aromatic [22] heteroporphyrins.
• Spectroscopic characterization (UV-Vis-NIR, NMR, Mass Spectrometry).
• Computational analysis to correlate structure with optical properties.

Main Results:

• Successful synthesis and full characterization of the target heteroporphyrins.
• Demonstrated significant absorption in the NIR region (700-1000 nm).
• Observed that fusion/annelation of precursor heterocycles enhances NIR absorption.

Conclusions:

• The synthesized aromatic [22] heteroporphyrins exhibit promising NIR absorption properties.
• Macrocycle structure, specifically heterocycle annelation, is crucial for tuning NIR absorption.
• These findings pave the way for developing new NIR-absorbing materials.