Red/NIR Thermally Activated Delayed Fluorescence from Aza-BODIPYs.

Area of Science:

• Organic Chemistry
• Photophysics
• Materials Science

Background:

• Developing long-lived red and near-infrared (NIR) fluorescent dyes is a significant challenge.
• Existing fluorescent probes often lack the required emission characteristics for advanced applications.

Purpose of the Study:

• To demonstrate the potential of the aza-BODIPY scaffold for creating thermally activated delayed fluorescent (TADF) probes emitting in the red and NIR regions.
• To explore the structure-property relationships governing the photophysical performance of these novel dyes.

Main Methods:

• Synthesis of novel aza-BODIPY derivatives with tailored energy and charge transfer properties.
• Photophysical characterization including emission spectra, fluorescence lifetimes, and quantum yields.
• Computational modeling to understand the photophysical mechanisms and structure-photonics interplay.

Main Results:

• Aza-BODIPY derivatives successfully achieved delayed fluorescence in the red spectral region (695-735 nm).
• Emission lifetimes exceeding 100 μs were recorded in aerated solutions at room temperature.
• Computational studies elucidated the role of molecular structure in achieving efficient thermally activated reverse intersystem crossing (RISC).

Conclusions:

• The aza-BODIPY skeleton is a viable platform for designing long-lived red and NIR TADF emitters.
• The synthetic tunability allows for precise control over stereoelectronic properties and photonic response.
• These novel aza-BODIPY systems offer a promising foundation for developing advanced optical materials with efficient and durable NIR emission.