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Symmetry-Breaking Directed Assembly in Achiral Point Groups for Circularly Polarized Room-Temperature Phosphorescence
Qihuan Li1, Yizhou Song1, Jiaqi He1
1State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.
Advanced Materials (Deerfield Beach, Fla.)
|August 11, 2025
Summary
Researchers developed new organic materials that emit circularly polarized room-temperature phosphorescence (CP-RTP) from achiral crystals. This breakthrough enables the creation of optically active phosphorescent signals in previously challenging systems.
Area of Science:
- Materials Science
- Organic Chemistry
- Photophysics
Background:
- Pure organic circularly polarized room-temperature phosphorescent (CP-RTP) materials are gaining attention for their unique photophysical properties.
- Creating optically active phosphorescent signals within achiral systems presents a significant challenge in materials design.
Purpose of the Study:
- To design and synthesize novel achiral organic materials exhibiting strong CP-RTP emission.
- To investigate the structure-property relationships governing CP-RTP in achiral systems.
- To overcome limitations in generating optically active phosphorescence from achiral point group materials.
Main Methods:
- Synthesis of two achiral organic crystals, 2CN4S and 2F4S.
- Characterization of their photophysical properties, including CP-RTP emission and photoluminescence dissymmetry factors (glum).
- Analysis of molecular conformations and supramolecular assembly using C─H···N hydrogen bonding and π-π interactions.
Main Results:
- Achiral crystals 2CN4S and 2F4S demonstrated strong CP-RTP emission.
- High photoluminescence dissymmetry factors (glum) were achieved: up to 5.5 × 10-2 (543 nm) for 2CN4S and 4.3 × 10-2 (550 nm) for 2F4S.
- The CP-RTP phenomenon was attributed to mirror-antiparallel molecular conformations and self-assembly into helical superstructures within the achiral crystal lattice.
Conclusions:
- A novel strategy for designing CP-RTP materials has been established.
- The study successfully overcame structural constraints in achieving optically active phosphorescence within achiral point group systems.
- The findings pave the way for new applications of organic phosphorescent materials.
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