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Tetraphenylethylene-Functionalized Neutral Radicals for Near-Infrared Photothermal Conversion
Chuan Yan1,2, Min Wang2, Jing Fang2
1College of Chemistry and Materials Science, Hengyang Normal University, Hengyang, Hunan 421008, China.
Organic Letters
|December 12, 2025
Summary
New all-twisted radicals with tetraphenylethene units show efficient near-infrared absorption and photothermal conversion. TTM-3PTPEA achieved a 59% conversion efficiency, demonstrating potential for photothermal applications.
Area of Science:
- Materials Science
- Organic Chemistry
- Photochemistry
Background:
- Intramolecular charge transfer (ICT) is crucial for developing advanced photofunctional materials.
- Tetraphenylethene (TPE) derivatives are known for their aggregation-induced emission and unique photophysical properties.
- Developing efficient near-infrared (NIR) absorbing and photothermal conversion materials is essential for various applications.
Purpose of the Study:
- To design and synthesize novel all-twisted radicals incorporating aniline-modified tetraphenylethene (PTPEA) units onto a TTM core.
- To investigate the photophysical properties, particularly NIR absorption and photothermal conversion efficiency, of these synthesized radicals.
- To evaluate the structure-property relationships, focusing on the impact of multiple PTPEA units on performance.
Main Methods:
- Chemical synthesis of TTM-PTPEA, TTM-2PTPEA, and TTM-3PTPEA radicals.
- Spectroscopic characterization including UV-Vis absorption and emission spectroscopy.
- Photothermal conversion efficiency measurements under NIR irradiation.
Main Results:
- The synthesized radicals exhibit strong NIR absorption attributed to efficient ICT interactions.
- The twisted molecular structure and intramolecular motions lead to silent emission and effective photothermal conversion.
- TTM-3PTPEA, with three PTPEA units, demonstrated a high NIR photothermal conversion efficiency of 59%.
Conclusions:
- The designed all-twisted radicals are promising NIR absorbers with significant photothermal conversion capabilities.
- The incorporation of multiple PTPEA units enhances photothermal performance, as exemplified by TTM-3PTPEA.
- These findings open avenues for developing advanced materials for photothermal applications using twisted radical architectures.
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