Circularly Polarized Room Temperature Red Phosphorescence from a [9]-Heterohelical Terrylene Diimide

Area of Science:

• Organic Chemistry
• Materials Science
• Photophysics

Background:

• Achieving circularly polarized room temperature phosphorescence (CP-RTP) in the red region is difficult due to stringent molecular design requirements.
• Simultaneously meeting criteria for high quantum yield circularly polarized luminescence and ambient phosphorescence in organic molecules remains a significant challenge.

Purpose of the Study:

• To devise a novel molecular design strategy for realizing CP-RTP in the red region.
• To synthesize and characterize a [9]-heterohelical terrylene diimide exhibiting CP-RTP.

Main Methods:

• Molecular design incorporating helical chirality and extended conjugation.
• Solvent polarity manipulation to tune chiroptical responses.
• Thin-film fabrication for room temperature phosphorescence measurements.

Main Results:

• Successfully designed and synthesized a [9]-heterohelical terrylene diimide with red-region chiroptical responses.
• Observed a four-fold increase in the dissymmetry factor upon switching solvent polarity.
• Demonstrated CP-RTP in a thin film, a first for rylene diimide-based helical systems.

Conclusions:

• The novel design strategy enables CP-RTP in organic molecules, specifically in the challenging red emission region.
• The synthesized molecule represents a significant advancement in the field of chiral organic optoelectronics.
• This work opens new avenues for developing advanced functional materials with tailored chiroptical and emissive characteristics.