Charge-Transfer Luminescence in a Molecular Donor-Acceptor Complex: Computational Insights

Area of Science:

• Materials Science
• Computational Chemistry
• Photophysics

Background:

• Donor-acceptor molecular complexes leverage charge-transfer (CT) states for applications.
• BODIPY-triphenylamine (TPA) dyads exhibit dual fluorescence, suggesting an emissive CT state.

Purpose of the Study:

• To computationally characterize the energetic alignment of excitonic and CT states in BODIPY-TPA complexes.
• To rationalize the observed dual fluorescence and emissive CT state.

Main Methods:

• Time-dependent density functional theory (TD-DFT) calculations.
• Utilized long-range corrected functionals and state-specific solvation.
• Analyzed energetic alignment and oscillator strengths.

Main Results:

• Achieved qualitatively correct alignment of exciton and CT states.
• Observed enhanced oscillator strength for the solvated CT state.
• Computational results agree with experimental observations.

Conclusions:

• The charge-transfer state in BODIPY-TPA dyads is optically bright, explaining dual fluorescence.
• Computational approach provides a foundation for exploring CT states.
• Enables rational design of novel donor-acceptor materials.