Highly Fluorescent Red-Light Emitting Bis(boranils) Based on Naphthalene Backbone

Area of Science:

• Organic Chemistry
• Materials Science
• Photophysics

Background:

• Boron-containing organic compounds, such as boranils, are of interest due to their unique electronic and optical properties.
• Tuning these properties is crucial for developing advanced functional materials.
• Developing efficient synthetic routes for novel boranil derivatives is an ongoing research area.

Purpose of the Study:

• To synthesize novel bis(boranil) derivatives with diverse substituents.
• To investigate the impact of structural modifications on their photophysical characteristics.
• To explore the potential of these compounds in creating materials with specific optical responses.

Main Methods:

• A one-pot synthesis protocol was employed using 1,5-dihydroxynaphthalene-2,6-dicarboxaldehyde as a precursor.
• Systematic variation of substituents at the boron atom and iminophenyl groups.
• Characterization of photophysical properties, including absorption and emission spectra, and fluorescence quantum yields.

Main Results:

• Ten novel bis(boranils) were successfully synthesized.
• Significant red-shifts in absorption (495-590 nm) and emission (533-683 nm) spectra were observed compared to simple boranils.
• Fluorescence quantum yields were substantially improved, reaching up to 83%.
• The introduction of electron-withdrawing (NO2) and electron-donating (NEt2) groups created a push-pull architecture within the π-conjugated bis(boranil) scaffold.

Conclusions:

• The developed one-pot protocol provides an efficient route to a library of bis(boranils).
• Substituent variation allows for facile tuning of photophysical properties, including significant spectral red-shifting and enhanced fluorescence.
• The synthesized bis(boranils) with push-pull architectures represent a novel class of materials with potential for optoelectronic applications.