Higher BODIPY Homologues-Synthesis, Reactivity, and Photoluminescence Investigations

Area of Science:

• Organometallic Chemistry
• Materials Science
• Photophysics

Background:

• Dipyrromethene (DPM) ligands are versatile scaffolds in coordination chemistry.
• Boron difluoride dipyrromethene (BODIPY) dyes are known for their strong fluorescence and photostability.
• Group 13 elements (e.g., Boron, Aluminum, Gallium, Indium) offer unique electronic properties when incorporated into organic frameworks.

Purpose of the Study:

• To synthesize and characterize novel ^MesDPM group 13 compounds with halide substituents.
• To investigate the photophysical properties, including absorption and fluorescence emission, of these new compounds.
• To explore the reactivity of these compounds for further functionalization.

Main Methods:

• Synthesis of ^MesDPM triel dihalides.
• Characterization using NMR, IR spectroscopy, and mass spectrometry.
• Solid-state structure determination via X-ray diffraction (XRD).
• Optical property analysis using UV/Vis and photoluminescence spectroscopy.
• Fluorescence quantum efficiency measurements in toluene solution.

Main Results:

• Successful synthesis of ^MesDPM group 13 compounds with chloride, bromide, and iodide substituents.
• X-ray diffraction confirmed the molecular structures.
• Compounds exhibited intense green fluorescence with absorption maxima around 520 nm and emission between 550-660 nm.
• Fluorescence quantum efficiencies reached up to 42% in toluene.
• Reactivity studies enabled access to mixed substituted compounds with alkyl and halide groups.

Conclusions:

• The study presents a new class of ^MesDPM group 13 compounds with tunable optical properties.
• These compounds represent advanced BODIPY dye analogues with significant fluorescence.
• The demonstrated reactivity opens pathways for creating diverse functional materials based on this scaffold.