BOPYRENPY: A Modular Strategy toward Structurally Tunable Seven-Membered BF₂-Chelated Chromophores.

Area of Science:

• Organic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Boron-dipyrromethene (BOPY) dyes are widely used due to their tunable photophysical properties.
• Developing novel BOPY derivatives with expanded ring systems presents opportunities for new functionalities.
• Seven-membered ring systems offer unique electronic and steric environments compared to traditional five-membered BOPY dyes.

Purpose of the Study:

• To establish a modular synthetic strategy for novel seven-membered BF2-chelated dyes.
• To explore the structural diversity and functional applicability of these new dye systems.
• To enable late-stage functionalization for fine-tuning photophysical properties.

Main Methods:

• Modular Knoevenagel condensation between 2-formylpyrroles and cyanomethylpyridine derivatives.
• Chelation reaction with BF2 to form the seven-membered ring system.
• Late-stage Suzuki coupling for incorporating donor units.

Main Results:

• Successful synthesis of seven-membered BF2-chelated dyes, termed BOPYRENPY.
• Demonstrated versatility in structural modification and functionalization.
• Achieved fine-tuning of fluorescence, Stokes shifts, and HOMO-LUMO energy levels through late-stage coupling.

Conclusions:

• BOPYRENPY represents a versatile platform for next-generation chromophores.
• The developed synthetic strategy allows for significant structural diversity.
• These novel seven-membered ring dyes offer tunable properties for advanced applications.