Benzo-Fused BOPAM Fluorophores: Synthesis, Post-functionalization, Photophysical Properties and Acid sensing...

Area of Science:

• Organic Chemistry
• Materials Science
• Photophysics

Background:

• Boron-containing organic molecules are of interest for their unique electronic and optical properties.
• Developing novel chromophores with tunable photophysical characteristics is crucial for advanced materials and sensing applications.

Purpose of the Study:

• To synthesize a new class of asymmetric boron chromophores, BOPAMs.
• To investigate the photophysical properties of benzo-fused BOPAMs and their derivatives.
• To explore the potential of these compounds in sensing applications, particularly for pH detection.

Main Methods:

• One-pot three-step synthesis of BOPAMs and their benzo-fused derivatives.
• Steady-state absorption and fluorescence emission spectroscopy at various temperatures and states.
• Computational methods to elucidate electronic and emissive properties.
• Post-functionalization of BOPAMs to tune their characteristics.

Main Results:

• Successful synthesis of [a] and [b]benzo-fused BOPAMs with post-functionalization capabilities.
• Systematic investigation revealing solvent-dependent fluorescence and solid-state properties.
• Observation of off-on fluorescence switching and intermolecular charge transfer states.
• Demonstration of fluorescence quenching via ICT and pH-dependent fluorescence enhancement in specific derivatives.

Conclusions:

• The synthesized BOPAMs represent a novel class of boron chromophores with diverse photophysical behaviors.
• These compounds exhibit tunable fluorescence and unique responses to solvent polarity and pH.
• The pH-sensitive BOPAM derivative shows promise for developing novel fluorescent pH sensors.