Helical π-Conjugated Structure Based on Complementary Helical Monomers with Circularly Polarized Luminescence

Area of Science:

• Organic Chemistry
• Materials Science
• Spectroscopy

Background:

• Development of π-conjugated helical systems is crucial for advanced optical materials.
• Chiroptical properties, particularly circularly polarized luminescence (CPL), are of significant interest for applications in displays and sensors.
• Designing flexible CPL-active molecules with tunable properties remains a challenge.

Purpose of the Study:

• To synthesize and characterize novel, fully π-conjugated helical systems incorporating [6]helicenes and ortho-phenylene vinylene (o-OPE) units.
• To investigate the chiroptical properties, including absorption and emission, of these enantiopure helical emitters.
• To elucidate the conformational dynamics influencing the optical behavior using computational methods.

Main Methods:

• Synthesis of enantiopure helical compounds featuring [6]helicenes and o-OPE units.
• Spectroscopic characterization of chiroptical properties, including absorption (gabs) and emission (glum).
• Combined Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations to analyze conformational dynamics.

Main Results:

• Successful development of fully π-conjugated helical systems with up to three helical loops.
• Observation of remarkable chiroptical properties with gabs up to 2.3 × 10⁻² and glum up to 1.3 × 10⁻² in methanol.
• Correlation between conformational dynamics and observed optical behavior established through DFT and MD studies.

Conclusions:

• The developed helical systems are promising enantiopure emitters with significant chiroptical activity.
• The combined DFT and MD approach provides a robust methodology for understanding flexible CPL-active systems.
• This work advances the design principles for advanced chiral optical materials.