Difluoro Dipyridomethene Boron Complexes: Synthesis, Characterization, and Ab Initio Calculations

Area of Science:

• Materials Science
• Organic Chemistry
• Photochemistry

Background:

• Molecular engineering of organic fluorophores is crucial for advanced optical applications.
• Boron complexes offer unique photophysical properties.
• Dipyridomethene frameworks are emerging scaffolds for functional materials.

Purpose of the Study:

• To synthesize and characterize novel fluorophores based on meso-cyano difluoro dipyridomethene boron complexes.
• To investigate the effect of functional groups on photophysical properties.
• To evaluate their potential as solution and solid-state emitters.

Main Methods:

• Suzuki-Miyaura and Sonogashira cross-coupling reactions for functionalization.
• Detailed structural, photophysical, and computational analyses.
• Time-Dependent Density Functional Theory (TD-DFT) and Coupled Cluster (CC2) calculations.

Main Results:

• Two series (a and b) of novel fluorophores were successfully synthesized with yields ranging from 14-90%.
• All derivatives exhibited excellent fluorescence emission (blue to orange) in solution upon blue light excitation.
• Series b, with an aryl substituent, demonstrated significantly large Stokes shifts.
• Promising emissive properties were observed for solid-state applications.

Conclusions:

• The synthesized dipyridomethene boron complexes are versatile fluorophores with tunable emission properties.
• Functionalization via cross-coupling reactions effectively modulates electronic and optical characteristics.
• These compounds hold potential for applications requiring efficient light emission and large Stokes shifts.